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  • This program runs but not correctly; the numbers aren't right.

    - by user320950
    this program runs but not correctly numbers arent right, i read numbers from a file and then when i am using them in the program they are not right.:brief decription of what i am trying to do can someone tell me if something doesnt look right. this is what i have to do: write a program that determines the grade dispersal for 100 students You are to read the exam scores into three arrays, one array for each exam. You must then calculate how many students scored A’s (90 or above), B’s (80 or above), C’s (70 or above), D’s (60 or above), and F’s (less than 60). Do this for each exam and write the distribution to the screen. // basic file operations #include <iostream> #include <fstream> using namespace std; int read_file_in_array(double exam[100][3]); double calculate_total(double exam1[], double exam2[], double exam3[]); // function that calcualates grades to see how many 90,80,70,60 //void display_totals(); double exam[100][3]; int main() { double go,go2,go3; double exam[100][3],exam1[100],exam2[100],exam3[100]; go=read_file_in_array(exam); go2=calculate_total(exam1,exam2,exam3); //go3=display_totals(); cout << go,go2,go3; return 0; } /* int display_totals() { int grade_total; grade_total=calculate_total(exam1,exam2,exam3); return 0; } */ double calculate_total(double exam1[],double exam2[],double exam3[]) { int calc_tot,above90=0, above80=0, above70=0, above60=0,i,j, fail=0; double exam[100][3]; calc_tot=read_file_in_array(exam); for(i=0;i<100;i++) { for (j=0; j<3; j++) { exam1[i]=exam[100][0]; exam2[i]=exam[100][1]; exam3[i]=exam[100][2]; if(exam[i][j] <=90 && exam[i][j] >=100) { above90++; { if(exam[i][j] <=80 && exam[i][j] >=89) { above80++; { if(exam[i][j] <=70 && exam[i][j] >=79) { above70++; { if(exam[i][j] <=60 && exam[i][j] >=69) { above60++; { if(exam[i][j] >=59) { fail++; } } } } } } } } } } } return 0; } int read_file_in_array(double exam[100][3]) { ifstream infile; int exam1[100]; int exam2[100]; int exam3[100]; infile.open("grades.txt");// file containing numbers in 3 columns if(infile.fail()) // checks to see if file opended { cout << "error" << endl; } int num, i=0,j=0; while(!infile.eof()) // reads file to end of line { for(i=0;i<100;i++) // array numbers less than 100 { for(j=0;j<3;j++) // while reading get 1st array or element infile >> exam[i][j]; infile >> exam[i][j]; infile >> exam[i][j]; cout << exam[i][j] << endl; { if (! (infile >> exam[i][j]) ) cout << exam[i][j] << endl; } exam[i][j]=exam1[i]; exam[i][j]=exam2[i]; exam[i][j]=exam3[i]; } infile.close(); } return 0; }

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  • PlayFramework with Scala and Morphia

    - by AKRamkumar
    I keep getting this exception: Oops: CannotCompileException An unexpected error occured caused by exception CannotCompileException: [source error] ds() not found in models.dc What is wrong with my code? Here is models.ds package models import com.google.code.morphia.annotations._ @Embedded class ds{ @Indexed var xs : Double=0 @Indexed var xc : Double=0 @Indexed var ys : Double=0 @Indexed var yc : Double=0 @Indexed var zs : Double=0 @Indexed var zc : Double=0 } Here is models.dc package models import com.google.code.morphia.annotations.{Embedded, Entity, Indexed} @Entity class dc{ @Indexed var name : String = null @Embedded var summary : ds = new ds() }

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  • Help with dynamic range compression function (audio)

    - by MusiGenesis
    I am writing a C# function for doing dynamic range compression (an audio effect that basically squashes transient peaks and amplifies everything else to produce an overall louder sound). I have written a function that does this (I think): public static void Compress(ref short[] input, double thresholdDb, double ratio) { double maxDb = thresholdDb - (thresholdDb / ratio); double maxGain = Math.Pow(10, -maxDb / 20.0); for (int i = 0; i < input.Length; i += 2) { // convert sample values to ABS gain and store original signs int signL = input[i] < 0 ? -1 : 1; double valL = (double)input[i] / 32768.0; if (valL < 0.0) { valL = -valL; } int signR = input[i + 1] < 0 ? -1 : 1; double valR = (double)input[i + 1] / 32768.0; if (valR < 0.0) { valR = -valR; } // calculate mono value and compress double val = (valL + valR) * 0.5; double posDb = -Math.Log10(val) * 20.0; if (posDb < thresholdDb) { posDb = thresholdDb - ((thresholdDb - posDb) / ratio); } // measure L and R sample values relative to mono value double multL = valL / val; double multR = valR / val; // convert compressed db value to gain and amplify val = Math.Pow(10, -posDb / 20.0); val = val / maxGain; // re-calculate L and R gain values relative to compressed/amplified // mono value valL = val * multL; valR = val * multR; double lim = 1.5; // determined by experimentation, with the goal // being that the lines below should never (or rarely) be hit if (valL > lim) { valL = lim; } if (valR > lim) { valR = lim; } double maxval = 32000.0 / lim; // convert gain values back to sample values input[i] = (short)(valL * maxval); input[i] *= (short)signL; input[i + 1] = (short)(valR * maxval); input[i + 1] *= (short)signR; } } and I am calling it with threshold values between 10.0 db and 30.0 db and ratios between 1.5 and 4.0. This function definitely produces a louder overall sound, but with an unacceptable level of distortion, even at low threshold values and low ratios. Can anybody see anything wrong with this function? Am I handling the stereo aspect correctly (the function assumes stereo input)? As I (dimly) understand things, I don't want to compress the two channels separately, so my code is attempting to compress a "virtual" mono sample value and then apply the same degree of compression to the L and R sample value separately. Not sure I'm doing it right, however. I think part of the problem may the "hard knee" of my function, which kicks in the compression abruptly when the threshold is crossed. I think I may need to use a "soft knee" like this: Can anybody suggest a modification to my function to produce the soft knee curve?

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  • Marshal struct to unmanaged array

    - by Pedro
    Hi guys, I have a C# struct to represent a cartesian vector, something like this: public struct Vector { private double x; private double y; private double z; //Some properties/methods } Now I have an unmanaged C dll that I need to call with P/Invoke. Some methods expect a double[3] parameter. The unmanaged C signature is something like void Cross(double a[3], double b[3], double c[3]); Is there any way to set up a P/Invoke signature so I can pass instances of my Vector struct and marshal them transparently to unmanaged double[3]? I would also need bidirectional marshaling as the unmanaged function needs to write the output to the argument array, so I guess I would need to marshal as LpArray. Any ideas? Thanks Pedro

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  • How can i call method from class but this method implemented from any interface?

    - by Phsika
    i try to call base.Alan(); in HacimBul. But base. dont give intellisense alan method public double HacimBul() { throw new Exception(); //return base..... -- how can i see base.Alan(); } namespace interfaceClass { class Program { static void Main(string[] args) { } } interface Ikenar { double kenar { get; set; } } interface Iyukseklik { double yuksekli {get; set;} } interface IAlan { double Alan(); } interface IHacim { double Hacim(); } class Alan : Ikenar, IAlan { public double kenar { get; set; } double IAlan.Alan() { return kenar * kenar; } } class Hacim : Alan, Iyukseklik { public double kenar { get; set; } public double yuksekli { get; set; } public double HacimBul() { throw new Exception(); //return base..... -- how can i see base.Alan(); } } }

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  • How can i call method from class but this method implamented from any interface?

    - by Phsika
    i try to call base.Alan(); in HacimBul. But base. dont give intellisense alan method public double HacimBul() { throw new Exception(); //return base..... -- how can i see base.Alan(); } namespace interfaceClass { class Program { static void Main(string[] args) { } } interface Ikenar { double kenar { get; set; } } interface Iyukseklik { double yuksekli {get; set;} } interface IAlan { double Alan(); } interface IHacim { double Hacim(); } class Alan : Ikenar, IAlan { public double kenar { get; set; } double IAlan.Alan() { return kenar * kenar; } } class Hacim : Alan, Iyukseklik { public double kenar { get; set; } public double yuksekli { get; set; } public double HacimBul() { throw new Exception(); //return base..... -- how can i see base.Alan(); } } }

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  • postgresql error - ERROR: input is out of range

    - by CaffeineIV
    The function below keeps returning this error message. I thought that maybe the double_precision field type was what was causing this, and I tried to use CAST, but either that's not it, or I didn't do it right... Help? Here's the error: ERROR: input is out of range CONTEXT: PL/pgSQL function "calculate_distance" line 7 at RETURN ********** Error ********** ERROR: input is out of range SQL state: 22003 Context: PL/pgSQL function "calculate_distance" line 7 at RETURN And here's the function: CREATE OR REPLACE FUNCTION calculate_distance(character varying, double precision, double precision, double precision, double precision) RETURNS double precision AS $BODY$ DECLARE earth_radius double precision; BEGIN earth_radius := 3959.0; RETURN earth_radius * acos(sin($2 / 57.2958) * sin($4 / 57.2958) + cos($2/ 57.2958) * cos($4 / 57.2958) * cos(($5 / 57.2958) - ($3 / 57.2958))); END; $BODY$ LANGUAGE 'plpgsql' VOLATILE COST 100; ALTER FUNCTION calculate_distance(character varying, double precision, double precision, double precision, double precision) OWNER TO postgres; //I tried changing (unsuccessfully) that RETURN line to: RETURN CAST( (earth_radius * acos(sin($2 / 57.2958) * sin($4 / 57.2958) + cos($2/ 57.2958) * cos($4 / 57.2958) * cos(($5 / 57.2958) - ($3 / 57.2958))) ) AS text);

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  • Representing robot's elbow angle in 3-D

    - by Onkar Deshpande
    I am given coordinates of two points in 3-D viz. shoulder point and object point(to which I am supposed to reach). I am also given the length from my shoulder-to-elbow arm and the length of my forearm. I am trying to solve for the unknown position(the position of the joint elbow). I am using cosine rule to find out the elbow angle. Here is my code - #include <stdio.h> #include <math.h> #include <stdlib.h> struct point { double x, y, z; }; struct angles { double clock_wise; double counter_clock_wise; }; double max(double a, double b) { return (a > b) ? a : b; } /* * Check if the combination can make a triangle by considering the fact that sum * of any two sides of a triangle is greater than the remaining side. The * overlapping condition of links is handled separately in main(). */ int valid_triangle(struct point p0, double l0, struct point p1, double l1) { double dist = sqrt(pow((fabs(p1.z - p0.z)), 2) + pow((fabs(p1.y - p0.y)), 2) + pow((fabs(p1.x - p0.x)), 2)); if((max(dist, l0) == dist) && max(dist, l1) == dist) { return (dist < (l0 + l1)); } else if((max(dist, l0) == l0) && (max(l0, l1) == l0)) { return (l0 < (dist + l1)); } else { return (l1 < (dist + l0)); } } /* * Cosine rule is used to find the elbow angle. Positive value indicates a * counter clockwise angle while negative value indicates a clockwise angle. * Since this problem has at max 2 solutions for any given position of P0 and * P1, I am returning a structure of angles which can be used to consider angles * from both direction viz. clockwise-negative and counter-clockwise-positive */ void return_config(struct point p0, double l0, struct point p1, double l1, struct angles *a) { double dist = sqrt(pow((fabs(p1.z - p0.z)), 2) + pow((fabs(p1.y - p0.y)), 2) + pow((fabs(p1.x - p0.x)), 2)); double degrees = (double) acos((l0 * l0 + l1 * l1 - dist * dist) / (2 * l0 * l1)) * (180.0f / 3.1415f); a->clock_wise = -degrees; a->counter_clock_wise = degrees; } int main() { struct point p0, p1; struct angles a; p0.x = 15, p0.y = 4, p0.z = 0; p1.x = 20, p1.y = 4, p1.z = 0; double l0 = 5, l1 = 8; if(valid_triangle(p0, l0, p1, l1)) { printf("Three lengths can make a valid configuration \n"); return_config(p0, l0, p1, l1, &a); printf("Angle of the elbow point (clockwise) = %lf, (counter clockwise) = %lf \n", a.clock_wise, a.counter_clock_wise); } else { double dist = sqrt(pow((fabs(p1.z - p0.z)), 2) + pow((fabs(p1.y - p0.y)), 2) + pow((fabs(p1.x - p0.x)), 2)); if((dist <= (l0 + l1)) && (dist > l0)) { a.clock_wise = -180.0f; a.counter_clock_wise = 180.0f; printf("Angle of the elbow point (clockwise) = %lf, (counter clockwise) = %lf \n", a.clock_wise, a.counter_clock_wise); } else if((dist <= fabs(l0 - l1)) && (dist < l0)){ a.clock_wise = -0.0f; a.counter_clock_wise = 0.0f; printf("Angle of the elbow point (clockwise) = %lf, (counter clockwise) = %lf \n", a.clock_wise, a.counter_clock_wise); } else printf("Given combination cannot make a valid configuration\n"); } return 0; } However, this solution makes sense only in 2-D. Because clockwise and counter-clockwise are meaningless without an axis and direction of rotation. Returning only an angle is technically correct but it leaves a lot of work for the client of this function to use the result in meaningful way. How can I make the changes to get the axis and direction of rotation ? Also, I want to know how many possible solution could be there for this problem. Please let me know your thoughts ! Any help is highly appreciated ...

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  • C++ cin keeps skipping.....

    - by user69514
    I am having problems with my program. WHen I run it, it asks the user for the album, the title, but then it just exits the loop without asking for the price and the sale tax. Any ideas what's going on? This is a sample run Discounts effective for September 15, 2010 Classical 8% Country 4% International 17% Jazz 0% Rock 16% Show 12% Are there more transactions? Y/N y Enter Artist of CD: Sevendust Enter Title of CD: Self titled Enter Genre of CD: Rock enter price Are there more transactions? Y/N Thank you for shopping with us! Program code: #include <iostream> #include <string> using namespace std; int counter = 0; string discount_tiles[] = {"Classical", "Country", "International", "Jazz", "Rock", "Show"}; int discount_amounts[] = {8, 4, 17, 0, 16, 12, 14}; string date = "September 15, 2010"; // Array Declerations //Artist array char** artist = new char *[100]; //Title array char** title = new char *[100]; //Genres array char** genres = new char *[100]; //Price array double* price[100]; //Discount array double* tax[100]; // sale price array double* sale_price[100]; //sale tax array double* sale_tax[100]; //cash price array double* cash_price[100]; //Begin Prototypes char* getArtist(); char* getTitle(); char* getGenre(); double* getPrice(); double* getTax(); unsigned int* AssignDiscounts(); void ReadTransaction (char ** artist, char ** title, char ** genre, float ** cash, float & taxrate, int albumcount); void computesaleprice(); bool AreThereMore (); //End Prototypes bool areThereMore () { char answer; cout << "Are there more transactions? Y/N" << endl; cin >> answer; if (answer =='y' || answer =='Y') return true; else return false; } char* getArtist() { char * artist= new char [100]; cout << "Enter Artist of CD: " << endl; cin.getline(artist,100); cin.ignore(); return artist; } char* getTitle() { char * title= new char [100]; cout << "Enter Title of CD: " << endl; cin.getline(title,100); cin.ignore(); return title; } char* getGenre() { char * genre= new char [100]; cout << "Enter Genre of CD: " << endl; cin.getline(genre,100); cin.ignore(); return genre; } double* getPrice() { //double* price = new double(); //cout << "Enter Price of CD: " << endl; //cin >> *price; //return price; double p = 0.0; cout<< "enter price" << endl; cin >> p; cin.ignore(); double* pp = &p; return pp; } double* getTax() { double* tax= new double(); cout << "Enter local sales tax: " << endl; cin >> *tax; return tax; } int findDiscount(string str){ if(str.compare(discount_tiles[0]) == 0) return discount_amounts[0]; else if(str.compare(discount_tiles[0]) == 0) return discount_amounts[1]; else if(str.compare(discount_tiles[0]) == 0) return discount_amounts[2]; else if(str.compare(discount_tiles[0]) == 0) return discount_amounts[3]; else if(str.compare(discount_tiles[0]) == 0) return discount_amounts[4]; else if(str.compare(discount_tiles[0]) == 0) return discount_amounts[5]; else{ cout << "Error in findDiscount function" << endl; return 0; } } void computesaleprice() { /** fill in array for all purchases **/ for( int i=0; i<=counter; i++){ double temp = *price[i]; temp -= findDiscount(genres[i]); double* tmpPntr = new double(); tmpPntr = &temp; sale_price[i] = tmpPntr; delete(&temp); delete(tmpPntr); } } void printDailyDiscounts(){ cout << "Discounts effective for " << date << endl; for(int i=0; i < 6; i++){ cout << discount_tiles[i] << "\t" << discount_amounts[i] << "%" << endl; } } //Begin Main int main () { for( int i=0; i<100; i++){ artist[i]=new char [100]; title[i]=new char [100]; genres[i]=new char [100]; price[i] = new double(0.0); tax[i] = new double(0.0); } // End Array Decleration printDailyDiscounts(); bool flag = true; while(flag == true){ if(areThereMore() == true){ artist[counter] = getArtist(); title[counter] = getTitle(); genres[counter] = getGenre(); price[counter] = getPrice(); //tax[counter] = getTax(); //counter++; flag = true; } else { flag = false; } } //compute sale prices //computesaleprice(); cout << "Thank you for shopping with us!" << endl; return 0; } //End Main /** void ReadTransaction (char ** artist, char ** title, char ** genre, float ** cash, float & taxrate, int albumcount) { strcpy(artist[albumcount],getArtist()); strcpy(title[albumcount],getTitle()); strcpy(genre[albumcount],getGenre()); //cash[albumcount][0]=computesaleprice();??????? //taxrate=getTax;?????????????? } * * */ unsigned int * AssignDiscounts() { unsigned int * discount = new unsigned int [7]; cout << "Enter Classical Discount: " << endl; cin >> discount[0]; cout << "Enter Country Discount: " << endl; cin >> discount[1]; cout << "Enter International Discount: " << endl; cin >> discount[2]; cout << "Enter Jazz Discount: " << endl; cin >> discount[3]; cout << "Enter Pop Discount: " << endl; cin >> discount[4]; cout << "Enter Rock Discount: " << endl; cin >> discount[5]; cout << "Enter Show Discount: " << endl; cin >> discount[6]; return discount; } /** char ** AssignGenres () { char ** genres = new char * [7]; for (int x=0;x<7;x++) genres[x] = new char [20]; strcpy(genres [0], "Classical"); strcpy(genres [1], "Country"); strcpy(genres [2], "International"); strcpy(genres [3], "Jazz"); strcpy(genres [4], "Pop"); strcpy(genres [5], "Rock"); strcpy(genres [6], "Show"); return genres; } **/ float getTax(float taxrate) { cout << "Please enter store tax rate: " << endl; cin >> taxrate; return taxrate; }

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  • Odd behavior when recursively building a return type for variadic functions

    - by Dennis Zickefoose
    This is probably going to be a really simple explanation, but I'm going to give as much backstory as possible in case I'm wrong. Advanced apologies for being so verbose. I'm using gcc4.5, and I realize the c++0x support is still somewhat experimental, but I'm going to act on the assumption that there's a non-bug related reason for the behavior I'm seeing. I'm experimenting with variadic function templates. The end goal was to build a cons-list out of std::pair. It wasn't meant to be a custom type, just a string of pair objects. The function that constructs the list would have to be in some way recursive, with the ultimate return value being dependent on the result of the recursive calls. As an added twist, successive parameters are added together before being inserted into the list. So if I pass [1, 2, 3, 4, 5, 6] the end result should be {1+2, {3+4, 5+6}}. My initial attempt was fairly naive. A function, Build, with two overloads. One took two identical parameters and simply returned their sum. The other took two parameters and a parameter pack. The return value was a pair consisting of the sum of the two set parameters, and the recursive call. In retrospect, this was obviously a flawed strategy, because the function isn't declared when I try to figure out its return type, so it has no choice but to resolve to the non-recursive version. That I understand. Where I got confused was the second iteration. I decided to make those functions static members of a template class. The function calls themselves are not parameterized, but instead the entire class is. My assumption was that when the recursive function attempts to generate its return type, it would instantiate a whole new version of the structure with its own static function, and everything would work itself out. The result was: "error: no matching function for call to BuildStruct<double, double, char, char>::Go(const char&, const char&)" The offending code: static auto Go(const Type& t0, const Type& t1, const Types&... rest) -> std::pair<Type, decltype(BuildStruct<Types...>::Go(rest...))> My confusion comes from the fact that the parameters to BuildStruct should always be the same types as the arguments sent to BuildStruct::Go, but in the error code Go is missing the initial two double parameters. What am I missing here? If my initial assumption about how the static functions would be chosen was incorrect, why is it trying to call the wrong function rather than just not finding a function at all? It seems to just be mixing types willy-nilly, and I just can't come up with an explanation as to why. If I add additional parameters to the initial call, it always burrows down to that last step before failing, so presumably the recursion itself is at least partially working. This is in direct contrast to the initial attempt, which always failed to find a function call right away. Ultimately, I've gotten past the problem, with a fairly elegant solution that hardly resembles either of the first two attempts. So I know how to do what I want to do. I'm looking for an explanation for the failure I saw. Full code to follow since I'm sure my verbal description was insufficient. First some boilerplate, if you feel compelled to execute the code and see it for yourself. Then the initial attempt, which failed reasonably, then the second attempt, which did not. #include <iostream> using std::cout; using std::endl; #include <utility> template<typename T1, typename T2> std::ostream& operator <<(std::ostream& str, const std::pair<T1, T2>& p) { return str << "[" << p.first << ", " << p.second << "]"; } //Insert code here int main() { Execute(5, 6, 4.3, 2.2, 'c', 'd'); Execute(5, 6, 4.3, 2.2); Execute(5, 6); return 0; } Non-struct solution: template<typename Type> Type BuildFunction(const Type& t0, const Type& t1) { return t0 + t1; } template<typename Type, typename... Rest> auto BuildFunction(const Type& t0, const Type& t1, const Rest&... rest) -> std::pair<Type, decltype(BuildFunction(rest...))> { return std::pair<Type, decltype(BuildFunction(rest...))> (t0 + t1, BuildFunction(rest...)); } template<typename... Types> void Execute(const Types&... t) { cout << BuildFunction(t...) << endl; } Resulting errors: test.cpp: In function 'void Execute(const Types& ...) [with Types = {int, int, double, double, char, char}]': test.cpp:33:35: instantiated from here test.cpp:28:3: error: no matching function for call to 'BuildFunction(const int&, const int&, const double&, const double&, const char&, const char&)' Struct solution: template<typename... Types> struct BuildStruct; template<typename Type> struct BuildStruct<Type, Type> { static Type Go(const Type& t0, const Type& t1) { return t0 + t1; } }; template<typename Type, typename... Types> struct BuildStruct<Type, Type, Types...> { static auto Go(const Type& t0, const Type& t1, const Types&... rest) -> std::pair<Type, decltype(BuildStruct<Types...>::Go(rest...))> { return std::pair<Type, decltype(BuildStruct<Types...>::Go(rest...))> (t0 + t1, BuildStruct<Types...>::Go(rest...)); } }; template<typename... Types> void Execute(const Types&... t) { cout << BuildStruct<Types...>::Go(t...) << endl; } Resulting errors: test.cpp: In instantiation of 'BuildStruct<int, int, double, double, char, char>': test.cpp:33:3: instantiated from 'void Execute(const Types& ...) [with Types = {int, int, double, double, char, char}]' test.cpp:38:41: instantiated from here test.cpp:24:15: error: no matching function for call to 'BuildStruct<double, double, char, char>::Go(const char&, const char&)' test.cpp:24:15: note: candidate is: static std::pair<Type, decltype (BuildStruct<Types ...>::Go(BuildStruct<Type, Type, Types ...>::Go::rest ...))> BuildStruct<Type, Type, Types ...>::Go(const Type&, const Type&, const Types& ...) [with Type = double, Types = {char, char}, decltype (BuildStruct<Types ...>::Go(BuildStruct<Type, Type, Types ...>::Go::rest ...)) = char] test.cpp: In function 'void Execute(const Types& ...) [with Types = {int, int, double, double, char, char}]': test.cpp:38:41: instantiated from here test.cpp:33:3: error: 'Go' is not a member of 'BuildStruct<int, int, double, double, char, char>'

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  • How to get a number closest to the average in c++?

    - by Alex Zielinski
    What I'm trying to achieve is to take the average of the numbers stored in the array and find the number which is closest to it. My code compiles, but has an error just after starting. I think it's something to do with the memory handling (I don't feel confident with pointers, etc. yet) Could some nice guy take a look at my code and tell me what's wrong with it? (don't be hard on me, I'm a beginner) #include <iostream> #include <cmath> using namespace std; double* aver(double* arr, size_t size, double& average); int main() { double arr[] = {1,2,3,4,5,7}; size_t size = sizeof(arr)/sizeof(arr[0]); double average = 0; double* p = aver(arr,size,average); cout << *p << " " << average << endl; } double* aver(double* arr, size_t size, double& average){ int i,j,sum; double* m = 0; int tmp[7]; for(i=0;i<size;i++) sum += arr[i]; average = sum/size; for(j=0;j<size;j++){ tmp[j] = arr[j] - average; if(abs(tmp[j])>*m) *m = tmp[j]; } return m; }

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  • How to iterate over modifed std::map values?

    - by Frank
    I have an std::map, and I would like to define an iterator that returns modified values. Typically, a std::map<int,double>::iterator iterates over std::pair<int,double>, and I would like the same behavior, just the double value is multiplied by a constant. I tried it with boost::transform_iterator, but it doesn't compile: #include <map> #include <boost/iterator/transform_iterator.hpp> #include <boost/functional.hpp> typedef std::map<int,double> Map; Map m; m[100] = 2.24; typedef boost::binder2nd< std::multiplies<double> > Function; typedef boost::transform_iterator<Function, Map::value_type*> MultiplyIter; MultiplyIter begin = boost::make_transform_iterator(m.begin(), Function(std::multiplies<double>(), 4)); // now want to similarly create an end iterator // and then iterate over the modified map The error is: error: conversion from 'boost ::transform_iterator< boost::binder2nd<multiplies<double> >, gen_map<int, double>::iterator , boost::use_default, boost::use_default >' to non-scalar type 'boost::transform_iterator< boost::binder2nd<multiplies<double> >, pair<const int, double> * , boost::use_default, boost::use_default >' requested What is gen_map and do I really need it? I adapted the transform_iterator tutorial code from here to write this code ...

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  • MySQL DDL error creating tables

    - by Alexandstein
    I am attempting to create tables for a MySQL database, but I am having some syntactical issues. It would seem that syntax checking is behaving differently between tables for some reason. While I've gotten all the other tables to go through, the table, 'stock' doesn't seem to be working, despite seeming to use the same syntax patterns. CREATE TABLE users ( user_id SMALLINT UNSIGNED NOT NULL AUTO_INCREMENT, username VARCHAR(30) NOT NULL, password CHAR(41) NOT NULL, date_joined DATETIME NOT NULL, funds DOUBLE UNSIGNED NOT NULL, PRIMARY KEY(user_id), UNIQUE KEY(username) ); CREATE TABLE owned_stocks ( id SMALLINT UNSIGNED NOT NULL AUTO_INCREMENT, user_id SMALLINT UNSIGNED NOT NULL, paid_price DOUBLE UNSIGNED NOT NULL, quantity MEDIUMINT UNSIGNED NOT NULL, purchase_date DATETIME NOT NULL, PRIMARY KEY(id) ); CREATE TABLE tracking_stocks ( ticker VARCHAR(5) NOT NULL, user_id SMALLINT UNSIGNED NOT NULL, PRIMARY KEY(ticker) ); CREATE TABLE stocks ( ticker VARCHAR(5) NOT NULL, last DOUBLE UNSIGNED NOT NULL, high DOUBLE UNSIGNED NOT NULL, low DOUBLE UNSIGNED NOT NULL, company_name VARCHAR(30) NOT NULL, last_updated INT UNSIGNED NOT NULL, change DOUBLE NOT NULL, percent_change DOUBLE NOT NULL, PRIMARY KEY(ticker) ); Am I just missing a really obvious syntactical issue? ERROR: #1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'change DOUBLE NOT NULL, percent_change DOUBLE NOT NULL, last DOUBLE' at line 4

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  • this program runs but not correctly:brief decription of what i am trying to do can someone tell me i

    - by user320950
    this is what i have to do: write a program that determines the grade dispersal for 100 students You are to read the exam scores into three arrays, one array for each exam. You must then calculate how many students scored A’s (90 or above), B’s (80 or above), C’s (70 or above), D’s (60 or above), and F’s (less than 60). Do this for each exam and write the distribution to the screen. // basic file operations #include <iostream> #include <fstream> using namespace std; int read_file_in_array(double exam[100][3]); double calculate_total(double exam1[], double exam2[], double exam3[]); // function that calcualates grades to see how many 90,80,70,60 //void display_totals(); double exam[100][3]; int main() { double go,go2,go3; double exam[100][3],exam1[100],exam2[100],exam3[100]; go=read_file_in_array(exam); go2=calculate_total(exam1,exam2,exam3); //go3=display_totals(); cout << go,go2,go3; return 0; } /* int display_totals() { int grade_total; grade_total=calculate_total(exam1,exam2,exam3); return 0; } */ double calculate_total(double exam1[],double exam2[],double exam3[]) { int calc_tot,above90=0, above80=0, above70=0, above60=0,i,j, fail=0; double exam[100][3]; calc_tot=read_file_in_array(exam); for(i=0;i<100;i++) { for (j=0; j<3; j++) { exam1[i]=exam[100][0]; exam2[i]=exam[100][1]; exam3[i]=exam[100][2]; if(exam[i][j] <=90 && exam[i][j] >=100) { above90++; { if(exam[i][j] <=80 && exam[i][j] >=89) { above80++; { if(exam[i][j] <=70 && exam[i][j] >=79) { above70++; { if(exam[i][j] <=60 && exam[i][j] >=69) { above60++; { if(exam[i][j] >=59) { fail++; } } } } } } } } } } } return 0; } int read_file_in_array(double exam[100][3]) { ifstream infile; int exam1[100]; int exam2[100]; int exam3[100]; infile.open("grades.txt");// file containing numbers in 3 columns if(infile.fail()) // checks to see if file opended { cout << "error" << endl; } int num, i=0,j=0; while(!infile.eof()) // reads file to end of line { for(i=0;i<100;i++) // array numbers less than 100 { for(j=0;j<3;j++) // while reading get 1st array or element infile >> exam[i][j]; infile >> exam[i][j]; infile >> exam[i][j]; cout << exam[i][j] << endl; { if (! (infile >> exam[i][j]) ) cout << exam[i][j] << endl; } exam[i][j]=exam1[i]; exam[i][j]=exam2[i]; exam[i][j]=exam3[i]; } infile.close(); } return 0; }

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  • this program runs but not correctly numbers arent right, i read numbers from a file and then when i

    - by user320950
    this is what i have to do: write a program that determines the grade dispersal for 100 students You are to read the exam scores into three arrays, one array for each exam. You must then calculate how many students scored A’s (90 or above), B’s (80 or above), C’s (70 or above), D’s (60 or above), and F’s (less than 60). Do this for each exam and write the distribution to the screen. // basic file operations #include <iostream> #include <fstream> using namespace std; int read_file_in_array(double exam[100][3]); double calculate_total(double exam1[], double exam2[], double exam3[]); // function that calcualates grades to see how many 90,80,70,60 //void display_totals(); double exam[100][3]; int main() { double go,go2,go3; double exam[100][3],exam1[100],exam2[100],exam3[100]; go=read_file_in_array(exam); go2=calculate_total(exam1,exam2,exam3); //go3=display_totals(); cout << go,go2,go3; return 0; } /* int display_totals() { int grade_total; grade_total=calculate_total(exam1,exam2,exam3); return 0; } */ double calculate_total(double exam1[],double exam2[],double exam3[]) { int calc_tot,above90=0, above80=0, above70=0, above60=0,i,j, fail=0; double exam[100][3]; calc_tot=read_file_in_array(exam); for(i=0;i<100;i++) { for (j=0; j<3; j++) { exam1[i]=exam[100][0]; exam2[i]=exam[100][1]; exam3[i]=exam[100][2]; if(exam[i][j] <=90 && exam[i][j] >=100) { above90++; { if(exam[i][j] <=80 && exam[i][j] >=89) { above80++; { if(exam[i][j] <=70 && exam[i][j] >=79) { above70++; { if(exam[i][j] <=60 && exam[i][j] >=69) { above60++; { if(exam[i][j] >=59) { fail++; } } } } } } } } } } } return 0; } int read_file_in_array(double exam[100][3]) { ifstream infile; int exam1[100]; int exam2[100]; int exam3[100]; infile.open("grades.txt");// file containing numbers in 3 columns if(infile.fail()) // checks to see if file opended { cout << "error" << endl; } int num, i=0,j=0; while(!infile.eof()) // reads file to end of line { for(i=0;i<100;i++) // array numbers less than 100 { for(j=0;j<3;j++) // while reading get 1st array or element infile >> exam[i][j]; infile >> exam[i][j]; infile >> exam[i][j]; cout << exam[i][j] << endl; { if (! (infile >> exam[i][j]) ) cout << exam[i][j] << endl; } exam[i][j]=exam1[i]; exam[i][j]=exam2[i]; exam[i][j]=exam3[i]; } infile.close(); } return 0; }

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  • sequential mandelbrot image creation

    - by visanio_learner
    can anyone tell me what is wrong in this code? i am getting an error in the main function, when i am calling the 'file_write' method function inside the main function, it says 'y' is not declared in this scope, but actually it was an argument that i have passed it in the method function earlier. is it a serious error? #include <stdio.h> #include <stdlib.h> #include <time.h> unsigned int width = 1500; unsigned int height = 1500; unsigned int max_iterations = 30000; unsigned int **color = NULL; double threshold = 4; double min_re = -2.0; double max_re = 1.0; double min_im = -1.2; double max_im = min_im+(max_re-min_re)*height/width; double x_factor = (max_re-min_re)/(width-1); double y_factor = (max_im-min_im)/(height-1); int file_write(int x, int y, double min_re, double max_im, double x_factor, double y_factor) { FILE *fractal = fopen("mandelbrot_imageSequential.ppm","w+"); if(fractal != NULL) { fprintf(fractal,"P6\n"); fprintf(fractal,"# %s\n", "Mandelbrot_imageSequential.ppm"); fprintf(fractal,"%d %d\n", height, width); fprintf(fractal,"255\n"); unsigned int R = 0, G = 0, B = 0; for(unsigned y = 0; y < height; ++y) { double c_im = max_im - y*y_factor; for(unsigned x = 0; x < width; ++x) { double c_re = min_re + x*x_factor; double Z_re = c_re, Z_im = c_im; bool image_inside = true; R = 0, G = 0, B = 0; for(unsigned n=0; n<max_iterations; ++n) { double Z_re2 = Z_re*Z_re, Z_im2 = Z_im*Z_im; if(Z_re2 + Z_im2 > threshold) { image_inside = false; G = n; if(G == 10) { G = 25, R = 10, B = 5; } break; } Z_im = 2 * Z_re * Z_im + c_im; Z_re = Z_re2 - Z_im2 + c_re; } if(image_inside) { putc(R, fractal); putc(G, fractal); putc(B, fractal); } else { putc(R, fractal); putc(G, fractal); putc(B, fractal); } } } fclose(fractal); return 0; } } int main(int argc, char *argv[]) { if(argc != 9) { printf("There is an error in the input given.\n"); return 0; } else { height = atoi(argv[1]); width = atoi(argv[2]); max_iterations = atoi(argv[3]); min_re = atof(argv[4]); max_re = atof(argv[5]); min_im = atof(argv[6]); max_im = atof(argv[7]); threshold = atoi(argv[8]); } color = (unsigned int**)malloc(height*sizeof(unsigned int*)); printf("height = %d\twidth = %d\tmaximum_iterations = %d\tminimum_x-value = %.2f\tmaximum_x-value = %.2f\tminimum_y-value = %.2f\tmaximum_y-value = %.2f\tthreshold_value = %.2f\t\n",height,width,max_iterations,min_re,max_re,min_im,max_im,threshold); int x; for(x = 0; x < height; x++) { color[x] = (unsigned int*)malloc(width*sizeof(unsigned int)); } time_t ts,te; time(&ts); file_write(x,y,min_re,max_im,x_factor,y_factor); time(&te); double diff = difftime(te,ts); printf("Total Time elapsed: %f\n",diff); for(x = 0; x < height; x++) { free(color[x]); } free(color); return 0; }

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  • Send C++ Structure to MSMQ Message

    - by Gobalakrishnan
    Hi, I am trying to send the below structure through MSMQ Message typedef struct { char cfiller[7]; short MsgCode; char cfiller1[11]; short MsgLength; char cfiller2[2]; } MESSAGECODE; typedef struct { MESSAGECODE Header; char DealerId[16]; char GroupId[16]; long Token; short Periodicity; double Deposit; double GrossExposureLimit; double NetExposureLimit; double NetSaleExposureLimit; double NetPositionLimit; double TurnoverLimit; double PendingOrdersLimit; double MTMLossLimit; double MaxSingleTransValue; long MaxSingleTransQty; double IMLimit; long NetQuantityLimit; } LIMITUPDATE; void main() { // // create queue // open queue // send message // OleInitialize(NULL); // have to init OLE // // declare some variables // IMSMQQueueInfoPtr qinfo("MSMQ.MSMQQueueInfo"); IMSMQQueuePtr qSend; IMSMQMessagePtr m("MSMQ.MSMQMessage"); LIMITUPDATE l1; l1.Header.MsgCode=26001; l1.Header.MsgLength=150; qinfo->PathName = ".\\private$\\q99"; m->Body = l1; qSend = qinfo->Open(MQ_SEND_ACCESS, MQ_DENY_NONE); m->Send(qSend); qSend->Close(); } while compiling i am getting the following error. Error 2 error C2664: 'IMSMQMessage::PutBody' : cannot convert parameter 1 from 'LIMITUPDATE' to 'const _variant_t &' c:\temp\msmq\msmq.cpp 58 msmq thank you.

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  • Accessing a Class Member from a First-Class Function

    - by dbyrne
    I have a case class which takes a list of functions: case class A(q:Double, r:Double, s:Double, l:List[(Double)=>Double]) I have over 20 functions defined. Some of these functions have their own parameters, and some of them also use the q, r, and s values from the case class. Two examples are: def f1(w:Double) = (d:Double) => math.sin(d) * w def f2(w:Double, q:Double) = (d:Double) => d * q * w The problem is that I then need to reference q, r, and s twice when instantiating the case class: A(0.5, 1.0, 2.0, List(f1(3.0), f2(4.0, 0.5))) //0.5 is referenced twice I would like to be able to instantiate the class like this: A(0.5, 1.0, 2.0, List(f1(3.0), f2(4.0))) //f2 already knows about q! What is the best technique to accomplish this? Can I define my functions in a trait that the case class extends? EDIT: The real world application has 7 members, not 3. Only a small number of the functions need access to the members. Most of the functions don't care about them.

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  • Array Concatenation in C#

    - by Betamoo
    1- How to smartly initialize an Array with 2 (or more) other arrays in C#? double[] d1=new double[5]; double[] d2=new double[3]; double[] dTotal=new double[8];// I need this to be {d1 then d2} 2- Another question: How to concatenate C# arrays efficiently? Thanks

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  • How to use boost::transform_iterator to iterate over modifed std::map values?

    - by Frank
    I have an std::map, and I would like to define an iterator that returns modified values. Typically, a std::map<int,double>::iterator iterates over std::pair<int,double>, and I would like the same behavior, just the double value is multiplied by a constant. I tried it with boost::transform_iterator, but it doesn't compile: #include <map> #include <boost/iterator/transform_iterator.hpp> #include <boost/functional.hpp> typedef std::map<int,double> Map; Map m; m[100] = 2.24; typedef boost::binder2nd< std::multiplies<double> > Function; typedef boost::transform_iterator<Function, Map::value_type*> MultiplyIter; MultiplyIter begin = boost::make_transform_iterator(m.begin(), Function(std::multiplies<double>(), 4)); // now want to similarly create an end iterator // and then iterate over the modified map The error is: error: conversion from 'boost ::transform_iterator< boost::binder2nd<multiplies<double> >, gen_map<int, double>::iterator , boost::use_default, boost::use_default >' to non-scalar type 'boost::transform_iterator< boost::binder2nd<multiplies<double> >, pair<const int, double> * , boost::use_default, boost::use_default >' requested What is gen_map and do I really need it? I adapted the transform_iterator tutorial code from here to write this code ...

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  • programs runs but values are not correct, all it says is stack around the variable "exam" was corrup

    - by user320950
    // basic file operations #include <iostream> #include <fstream> using namespace std; int read_file_in_array(double exam[100][3]); double calculate_total(double exam1[], double exam2[], double exam3[]); // function that calcualates grades to see how many 90,80,70,60 //void display_totals(); double exam[100][3]; int main() { double go,go2,go3; double exam[100][3],exam1[100],exam2[100],exam3[100]; go=read_file_in_array(exam); go2=calculate_total(exam1,exam2,exam3); //go3=display_totals(); cout << go,go2,go3; return 0; } /* int display_totals() { int grade_total; grade_total=calculate_total(exam1,exam2,exam3); return 0; } */ double calculate_total(double exam1[],double exam2[],double exam3[]) { int calc_tot,above90=0, above80=0, above70=0, above60=0,i,j, fail=0; double exam[100][3]; calc_tot=read_file_in_array(exam); for(i=0;i<100;i++) { for (j=0; j<3; j++) { exam1[i]=exam[100][0]; exam2[i]=exam[100][1]; exam3[i]=exam[100][2]; if(exam[i][j] <=90 && exam[i][j] >=100) { above90++; { if(exam[i][j] <=80 && exam[i][j] >=89) { above80++; { if(exam[i][j] <=70 && exam[i][j] >=79) { above70++; { if(exam[i][j] <=60 && exam[i][j] >=69) { above60++; { if(exam[i][j] >=59) { fail++; } } } } } } } } } } } return 0; } int read_file_in_array(double exam[100][3]) { ifstream infile; int exam1[100]; int exam2[100]; int exam3[100]; infile.open("grades.txt");// file containing numbers in 3 columns if(infile.fail()) // checks to see if file opended { cout << "error" << endl; } int num, i=0,j=0; while(!infile.eof()) // reads file to end of line { for(i=0;i<100;i++) // array numbers less than 100 { for(j=0;j<3;j++) // while reading get 1st array or element infile >> exam[i][j]; infile >> exam[i][j]; infile >> exam[i][j]; cout << exam[i][j] << endl; { if (! (infile >> exam[i][j]) ) cout << exam[i][j] << endl; } exam[i][j]=exam1[i]; exam[i][j]=exam2[i]; exam[i][j]=exam3[i]; } infile.close(); } return 0; }

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  • Get array's key recursively and create underscore seperated string.

    - by Nehal
    Hello Everyone, Right now i got an array which has some sort of information and i need to create a table from it. e.g. Student{ [Address]{ [StreetAddress] =>"Some Street" [StreetName] => "Some Name" } [Marks1] => 100 [Marks2] => 50 } Now I want to create database table like which contain the fields name as : Student_Address_StreetAddress Student_Address_StreetName Student_Marks1 Student_Marks2 It should be recursive so from any depth of array it can create the string in my format.

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  • Conversion from C code to CudaC code I get unpredictable results

    - by Abhi
    include include include include define pi 3.14159265359 lo*lo*p-2*mu,freq=2.25*1e6,wavelength=(long double)lo/freq,dh=(long double)wavelength/ 30.0,dt=(long double)dh/(lo*1.5); (1000*dh)); (p*dh),lambdaplus2mudtbydh=(lambda+2*mu)*dt/dh,lambdadtbydh=lambda*dt/dh,dtmubydh=dt*mu/ dh; double**U,long double**V){ for(int k=0,l=0;k<=yno-1 && l<=yno;k++,l++){ U[i+1][l]+=dtbyrhodh*(X[i+1][l+1]-X[i+1][l]+Z[i+1][l]- Z[i][l]); [k+1]-Y[j][k+1]); } double**U,long double**V){ for(int k=0,l=0;k<=yno-1 && l<=yno;k++,l++){ U[i+1][k])+lambdadtbydh*(V[i+1][k+1]-V[i][k+1]); V[i][k+1])+lambdadtbydh*(U[i+1][k+1]-U[i+1][k]); U[j][l]); int main(){ clock_t start,end; long double time_taken; start=clock(); long double **X,**Y,**U,**V,**Z;int n=1; X=Make2DDoubleArray(xno+2,yno+2); Y=Make2DDoubleArray(xno+2,yno+2); Z=Make2DDoubleArray(xno+1,yno+1); U=Make2DDoubleArray(xno+2,yno+2); V=Make2DDoubleArray(xno+2,yno+2); for (n=1;n<=timesteps;n++){ } end=clock(); time_taken=(long double)(end-start)/CLOCKS_PER_SEC; printf("Time elapsed is %Lf\nGRID Size:%Lf*%Lf\nTime Steps Taken:%d\n",time_taken,(xno),floor(yno),n); return 0; }

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  • Java Newbie can't do simple Math, operator error

    - by elguapo-85
    Trying to do some really basic math here, but my lack of understanding of Java is causing some problems for me. double[][] handProbability = new double[][] {{0,0,0},{0,0,0},{0,0,0}}; double[] handProbabilityTotal = new double[] {0,0,0}; double positivePot = 0; double negativePot = 0; int localAhead = 0; int localTied = 1; int localBehind = 2; //do some stuff that adds values to handProbability and handProbabilityTotal positivePot = (handProbability[localBehind][localAhead] + (handProbability[localBehind][localTied] / 2.0) + (handProbability[localTied][localAhead] / 2.0) ) / (handProbabilityTotal[localBehind] + (handProbability[localTied] / 2.0)); negativePot = (handProbability[localAhead][localBehind] + (handProbability[localAhead][localTied] / 2.0) + (handProbability[localTied][localBehind] / 2.0) ) / (handProbabilityTotal[localAhead] + (handProbabilityTotal[localTied] / 2.0)); The last two lines are giving me problems (sorry for their lengthiness). Compiler Errors: src/MyPokerClient/MyPokerClient.java:180: operator / cannot be applied to double[],double positivePot = ( handProbability[localBehind][localAhead] + (handProbability[localBehind][localTied] / 2.0) + (handProbability[localTied][localAhead] / 2.0) ) / (handProbabilityTotal[localBehind] + (handProbability[localTied] / 2.0) ); ^ src/MyPokerClient/MyPokerClient.java:180: operator + cannot be applied to double, positivePot = ( handProbability[localBehind][localAhead] + (handProbability[localBehind][localTied] / 2.0) + (handProbability[localTied][localAhead] / 2.0) ) / (handProbabilityTotal[localBehind] + (handProbability[localTied] / 2.0) ); ^ src/MyPokerClient/MyPokerClient.java:180: operator / cannot be applied to double, positivePot = ( handProbability[localBehind][localAhead] + (handProbability[localBehind][localTied] / 2.0) + (handProbability[localTied][localAhead] / 2.0) ) / (handProbabilityTotal[localBehind] + (handProbability[localTied] / 2.0) ); Not really sure what the problem is. You shouldn't need anything special for basic math, right?

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  • 1 error with an array "missing return statement"

    - by danielit0w
    import javax.swing.JOptionPane; public class Mate { double suma (double x1,double x2) {return x1+x2;} double suma (double x1,double x2,double x3) {return x1+x2+x3;} double suma (int num [ ]) {int i=num.length; int j=0; int s=0; for(j=0;j < i;j++) {return (double)(s);}}} // here appears the error "missing return statement" class AplicacionMate {public static void main (String arg []) {int n[ ]={5,4,3,2,1}; double r=0.0; Mate m=new Mate ( ); r=m.suma(5,4); JOptionPane.showMessageDialog(null,"La suma 1="+r); r=m.suma(5,5,4); JOptionPane.showMessageDialog(null,"La suma 2="+r); r=m.suma(n); JOptionPane.showMessageDialog(null,"La suma del arreglo="+r); System.exit(0);}}

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