Search Results

Search found 2898 results on 116 pages for 'sum of digits'.

Page 28/116 | < Previous Page | 24 25 26 27 28 29 30 31 32 33 34 35  | Next Page >

• How do I select the first row per group in an SQL Query?

  - by mafutrct

  I've got this SQL query: SELECT Foo, Bar, SUM(Values) AS Sum FROM SomeTable GROUP BY Foo, Bar ORDER BY Foo DESC, Sum DESC This results in an output similar to this: 47 1 100 47 0 10 47 2 10 46 0 100 46 1 10 46 2 10 44 0 2 I'd like to have only the first row per Foo and ignore the rest. 47 1 100 46 0 100 44 0 2 How do I do that?

  Read the article

• Usage of Assert.Inconclusive

  - by Johannes Rudolph

  Hi, Im wondering how someone should use Assert.Inconclusive(). I'm using it if my Unit test would be about to fail for a reason other than what it is for. E.g. i have a method on a class that calculates the sum of an array of ints. On the same class there is also a method to calculate the average of the element. It is implemented by calling sum and dividing it by the length of the array. Writing a Unit test for Sum() is simple. However, when i write a test for Average() and Sum() fails, Average() is likely to fail also. The failure of Average is not explicit about the reason it failed, it failed for a reason other than what it should test for. That's why i would check if Sum() returns the correct result, otherwise i Assert.Inconclusive(). Is this to be considered good practice? What is Assert.Inconclusive intended for? Or should i rather solve the previous example by means of an Isolation Framework?

  Read the article

• Rewriting a for loop in pure NumPy to decrease execution time

  - by Statto

  I recently asked about trying to optimise a Python loop for a scientific application, and received an excellent, smart way of recoding it within NumPy which reduced execution time by a factor of around 100 for me! However, calculation of the B value is actually nested within a few other loops, because it is evaluated at a regular grid of positions. Is there a similarly smart NumPy rewrite to shave time off this procedure? I suspect the performance gain for this part would be less marked, and the disadvantages would presumably be that it would not be possible to report back to the user on the progress of the calculation, that the results could not be written to the output file until the end of the calculation, and possibly that doing this in one enormous step would have memory implications? Is it possible to circumvent any of these? import numpy as np import time def reshape_vector(v): b = np.empty((3,1)) for i in range(3): b[i][0] = v[i] return b def unit_vectors(r): return r / np.sqrt((r*r).sum(0)) def calculate_dipole(mu, r_i, mom_i): relative = mu - r_i r_unit = unit_vectors(relative) A = 1e-7 num = A*(3*np.sum(mom_i*r_unit, 0)*r_unit - mom_i) den = np.sqrt(np.sum(relative*relative, 0))**3 B = np.sum(num/den, 1) return B N = 20000 # number of dipoles r_i = np.random.random((3,N)) # positions of dipoles mom_i = np.random.random((3,N)) # moments of dipoles a = np.random.random((3,3)) # three basis vectors for this crystal n = [10,10,10] # points at which to evaluate sum gamma_mu = 135.5 # a constant t_start = time.clock() for i in range(n[0]): r_frac_x = np.float(i)/np.float(n[0]) r_test_x = r_frac_x * a[0] for j in range(n[1]): r_frac_y = np.float(j)/np.float(n[1]) r_test_y = r_frac_y * a[1] for k in range(n[2]): r_frac_z = np.float(k)/np.float(n[2]) r_test = r_test_x +r_test_y + r_frac_z * a[2] r_test_fast = reshape_vector(r_test) B = calculate_dipole(r_test_fast, r_i, mom_i) omega = gamma_mu*np.sqrt(np.dot(B,B)) # write r_test, B and omega to a file frac_done = np.float(i+1)/(n[0]+1) t_elapsed = (time.clock()-t_start) t_remain = (1-frac_done)*t_elapsed/frac_done print frac_done*100,'% done in',t_elapsed/60.,'minutes...approximately',t_remain/60.,'minutes remaining'

  Read the article

• Add opening and closing balance columns

  - by user1862899

  i have a table like this: StockNumber|InventoryName|Year|Month|Adj|iss|piss|Tsfr|return|rdj|rpo|xefr alb001 clinic1 2010 1 4 5 5 5 6 5 4 10 alb001 Clinic1 2010 2 10 2 2 3 3 4 4 4 alb001 Clinic1 2010 4 11 3 5 77 90 78 9 6 alb001 Clinic1 2010 5 10 2 2 3 3 4 4 4 i want to add a closing balance column which will be sum(return+rdj+rpo+xefr) - sum(adj+iss+piss+tsfr) i also want to add the opening balance column which will be the be the closing balance of the previous month. i will then calculate the current months balance as OpeningBalance + sum(return+rdj+rpo+xefr) - sum(adj+iss+piss+tsfr) = ClosingBalance NB.The Year and Month columns are floats and also want to change them to date format. i am newbie to sql and crystal reports....i want a query to help me achieve the tasks of developing a report that has the opening and closing balance columns,the opening balance being the previous closing balance.....thank you for your help....

  Read the article

• What does a Java static method look like in Ruby?

  - by Hosh

  In Java, a 'static method' would look like this: class MyUtils { . . . public static double mean(int[] p) { int sum = 0; // sum of all the elements for (int i=0; i<p.length; i++) { sum += p[i]; } return ((double)sum) / p.length; } . . . } // Called from outside the MyUtils class. double meanAttendance = MyUtils.mean(attendance); What's the equivalent 'Ruby way' of writing a 'static method'?

  Read the article

• GROUP BY ID range?

  - by d0ugal

  Given a data set like this; +-----+---------------------+--------+ | id | date | result | +-----+---------------------+--------+ | 121 | 2009-07-11 13:23:24 | -1 | | 122 | 2009-07-11 13:23:24 | -1 | | 123 | 2009-07-11 13:23:24 | -1 | | 124 | 2009-07-11 13:23:24 | -1 | | 125 | 2009-07-11 13:23:24 | -1 | | 126 | 2009-07-11 13:23:24 | -1 | | 127 | 2009-07-11 13:23:24 | -1 | | 128 | 2009-07-11 13:23:24 | -1 | | 129 | 2009-07-11 13:23:24 | -1 | | 130 | 2009-07-11 13:23:24 | -1 | | 131 | 2009-07-11 13:23:24 | -1 | | 132 | 2009-07-11 13:23:24 | -1 | | 133 | 2009-07-11 13:23:24 | -1 | | 134 | 2009-07-11 13:23:24 | -1 | | 135 | 2009-07-11 13:23:24 | -1 | | 136 | 2009-07-11 13:23:24 | -1 | | 137 | 2009-07-11 13:23:24 | -1 | | 138 | 2009-07-11 13:23:24 | 1 | | 139 | 2009-07-11 13:23:24 | 0 | | 140 | 2009-07-11 13:23:24 | -1 | +-----+---------------------+--------+ How would I go about grouping the results by day 5 records at a time. The above results is part of the live data, there is over 100,000 results rows in the table and its growing. Basically I want to measure the change over time, so want to take a SUM of the result every X records. In the real data I'll be doing it ever 100 or 1000 but for the data above perhaps every 5. If i could sort it by date I would do something like this; SELECT DATE_FORMAT(date, '%h%i') ym, COUNT(result) 'Total Games', SUM(result) as 'Score' FROM nn_log GROUP BY ym; I can't figure out a way of doing something similar with numbers. The order is sorted by the date but I hope to split the data up every x results. It's safe to assume there are no blank rows. Doing it above with the data you could do multiple selects like; SELECT SUM(result) FROM table LIMIT 0,5; SELECT SUM(result) FROM table LIMIT 5,5; SELECT SUM(result) FROM table LIMIT 10,5; Thats obviously not a very good way to scale up to a bigger problem. I could just write a loop but I'd like to reduce the number of queries.

  Read the article

• how to define a structural type that refers to itself?

  - by IttayD

  I want to create a method sum that I can call on different types, specifically sum(1,2). def sum[A](a1: A, a2: A) = a1 + a2 This fails because the compiler can't tell if A has a method '+' I tried to define a structural type: type Addable = {def +(a: Addable)} This fails because of an illegal cyclic reference How can I achieve this in a type safe way without requiring A to extend a specific trait?

  Read the article

• how to convert sql union to linq

  - by lowlyintern

  I have the following Transact SQL query using a union. I need some pointers as to how this would look in LINQ i.e some examples wouldbe nice or if anyone can recommend a good tutorial on UNIONS in linq. select top 10 Barcode, sum(ItemDiscountUnion.AmountTaken) from (SELECT d.Barcode,SUM(AmountTaken) AmountTaken FROM [Aggregation].[dbo].[DiscountPromotion] d GROUP BY d.Barcode UNION ALL SELECT i.Barcode,SUM(AmountTaken) AmountTaken FROM [Aggregation].[dbo].ItemSaleTransaction i group by i.Barcode) ItemDiscountUnion group by Barcode

  Read the article

• When does the call() method get called in a Java Executor using Callable objects?

  - by MalcomTucker

  This is some sample code from an example. What I need to know is when call() gets called on the callable? What triggers it? public class CallableExample { public static class WordLengthCallable implements Callable { private String word; public WordLengthCallable(String word) { this.word = word; } public Integer call() { return Integer.valueOf(word.length()); } } public static void main(String args[]) throws Exception { ExecutorService pool = Executors.newFixedThreadPool(3); Set<Future<Integer>> set = new HashSet<Future<Integer>>(); for (String word: args) { Callable<Integer> callable = new WordLengthCallable(word); Future<Integer> future = pool.submit(callable); //**DOES THIS CALL call()?** set.add(future); } int sum = 0; for (Future<Integer> future : set) { sum += future.get();//**OR DOES THIS CALL call()?** } System.out.printf("The sum of lengths is %s%n", sum); System.exit(sum); } }

  Read the article

• Will this ever result in a stack overflow error?

  - by David

  Will incrementing the instance variables of an object ever lead to a stack overflow error? For example: This method (java) will cause a stack overflow error: class StackOverflow { public static void StackOverflow (int x) { System.out.println (x) ; StackOverflow(x+1) ; } public static void main (String[]arg) { StackOverflow (0) ; } but will this?: (..... is a gap that i've put in to shorten the code. its long enough as it is.) import java.util.*; class Dice { String name ; int x ; int[] sum ; .... public Dice (String name) { this.name = name ; this.x = 0 ; this.sum = new int[7] ; } .... public static void main (String[] arg) { Dice a1 = new Dice ("a1") ; for (int i = 0; i<6000000; i++) { a1.roll () ; printDice(a1) ; } } .... public void roll () { this.x = randNum(1, this.sum.length) ; this.sum[x] ++ ; } public static int randNum (int a, int b) { Random random = new Random() ; int c = (b-a) ; int randomNumber = ((random.nextInt(c)) + a) ; return randomNumber ; } public static void printDice (Dice Dice) { System.out.println (Dice.name) ; System.out.println ("value: "+Dice.x) ; printValues (Dice) ; } public static void printValues (Dice Dice) { for (int i = 0; i<Dice.sum.length; i++) System.out.println ("#of "+i+"'s: "+Dice.sum[i]) ; } } The above doesn't currently cause a stack overflow error but could i get it too if i changed this line in main: for (int i = 0; i<6000000; i++) so that instead of 6 million something sufficiently high were there?

  Read the article

• Splitting a double vector into equal parts

  - by Cosmin

  Greetings, Any input on a way to divide a std::vector into two equal parts ? I need to find the smallest possible difference between |part1 - part2|. This is how I'm doing it now, but from what you can probably tell it will yield a non-optimal split in some cases. auto mid = std::find_if(prim, ultim, [&](double temp) -> bool { if(tempsum >= sum) return true; tempsum += temp; sum -= temp; return false; }); The vector is sorted, highest to lowest, values can indeed appear twice. I'm not expecting part1 and part2 to have the same numbers of elements, but sum(part1) should be as close as possible to sum(part2) For example if we would have { 2.4, 0.12, 1.26, 0.51, 0.70 }, the best split would be { 2.4, 0.12 } and { 1.26, 0.51, 0.70 }. If it helps, I'm trying to achieve the splitting algorithm for the Shannon Fano encoding. Any input is appreciated, thanks!

  Read the article

• Should not a tail-recursive function also be faster?

  - by Balint Erdi

  I have the following Clojure code to calculate a number with a certain "factorable" property. (what exactly the code does is secondary). (defn factor-9 ([] (let [digits (take 9 (iterate #(inc %) 1)) nums (map (fn [x] ,(Integer. (apply str x))) (permutations digits))] (some (fn [x] (and (factor-9 x) x)) nums))) ([n] (or (= 1 (count (str n))) (and (divisible-by-length n) (factor-9 (quot n 10)))))) Now, I'm into TCO and realize that Clojure can only provide tail-recursion if explicitly told so using the recur keyword. So I've rewritten the code to do that (replacing factor-9 with recur being the only difference): (defn factor-9 ([] (let [digits (take 9 (iterate #(inc %) 1)) nums (map (fn [x] ,(Integer. (apply str x))) (permutations digits))] (some (fn [x] (and (factor-9 x) x)) nums))) ([n] (or (= 1 (count (str n))) (and (divisible-by-length n) (recur (quot n 10)))))) To my knowledge, TCO has a double benefit. The first one is that it does not use the stack as heavily as a non tail-recursive call and thus does not blow it on larger recursions. The second, I think is that consequently it's faster since it can be converted to a loop. Now, I've made a very rough benchmark and have not seen any difference between the two implementations although. Am I wrong in my second assumption or does this have something to do with running on the JVM (which does not have automatic TCO) and recur using a trick to achieve it? Thank you.

  Read the article

• tricky interview question for C++

  - by Alexander

  Given the code below. How would you create/implement SR.h so that it produces the correct output WITHOUT any asterix in your solution? I got bummed by this question #include <cstdio> #include "SR.h" int main() { int j = 5; int a[] = {10, 15}; { SR x(j), y(a[0]), z(a[1]); j = a[0]; a[0] = a[1]; a[1] = j; printf("j = %d, a = {%d, %d}\n", j, a[0], a[1]); } printf("j = %d, a = {%d, %d}\n", j, a[0], a[1]); } //output j = 10, a = {15, 10} j = 5, a = {10, 15} #include <cstdio> #include "SR.h" int main() { int sum = 0; for (int i = 1; i < 100; i++) { SR ii(i); while (i--) sum += i; } printf("sum = %d\n", sum); } //The output is "sum = 161700".

  Read the article

• Combining 2 Linq queries into 1

  - by Mike Fielden

  Given the following information, how can I combine these 2 linq queries into 1. Having a bit of trouble with the join statement. 'projectDetails' is just a list of ProjectDetails ProjectDetails (1 to many) PCardAuthorizations ProjectDetails (1 to many) ExpenditureDetails Notice I am grouping by the same information and selecting the same type of information var pCardAccount = from c in PCardAuthorizations where projectDetails.Contains(c.ProjectDetail) && c.RequestStatusId == 2 group c by new { c.ProjectDetail, c.ProgramFund } into g select new { Key = g.Key, Sum = g.Sum(x => x.Amount) }; var expenditures = from d in ExpenditureDetails where projectDetails.Contains(d.ProjectDetails) && d.Expenditures.ExpenditureTypeEnum == 0 group d by new { d.ProjectDetails, d.ProgramFunds } into g select new { Key = g.Key, Sum = g.Sum(y => y.ExpenditureAmounts.FirstOrDefault(a => a.IsCurrent && !a.RequiresAudit).CommittedMonthlyRecords.ProjectedEac) };

  Read the article

• search for a string , and add if it matches

  - by Sharat Chandra

  I have a file that has 2 columns as given below.... 101 6 102 23 103 45 109 36 101 42 108 21 102 24 109 67 and so on...... I want to write a script that adds the values from 2nd column if their corresponding first column matches for example add all 2nd column values if it's 1st column is 101 add all 2nd column values if it's 1st colummn is 102 add all 2nd column values if it's 1st colummn is 103 and so on ... i wrote my script like this , but i'm not getting the correct result awk '{print $1}' data.txt > col1.txt while read line do awk ' if [$1 == $line] sum+=$2; END {print "Sum for time stamp", $line"=", sum}; sum=0' data.txt done < col1.txt

  Read the article

• Scanning, Checking, Converting, Copying values ... How to ? -- C --

  - by ZaZu

  Hi there, Its been a while now and im still trying to get a certain code to work. I asked some question about different commands etc. before, but now I hope this is the final one (combining all questions in one code). I basically want to : *Scan an input (should be character ? ) *Check if its a number *If not, return error *Convert that character into a float number *Copy the value to another variable ( I called it imp here) Here is what I came up with : #include<stdio.h> #include<stdlib.h> #include<ctype.h> main(){ int digits; float imp=0; int alpha; do{ printf("Enter input\n\n"); scanf("\n%c",&alpha); digits=isdigit(alpha); if(digits==0){ printf("error\n\n"); } imp=atof(alpha); }while(digits==0); } The problem is this code does not work at all ... It gives me that atof must be of a const char and whenever I try changing it around, it just keeps failing. I am frustrated and forced to ask here, because I believe I have tried alot and I keep failing, but I wont be relieved until I get it to work xD So I really need your help guys. Please tell me why isnt this code working, what am I doing wrong ? I am still learning C and really appreciate your help :)

  Read the article

• extract variables from an expression using javascript regexp

  - by powerboy

  For example, here is a string representing an expression: var str = 'total = sum(price * qty) * 1.09875'; I want to extract variables (i.e., 'total', 'price' and 'qty' but not 'sum' since 'sum' is a function name) from this expression. What is the regexp pattern in javascript? Variable name consists of letters, digits, or the underscore, beginning with letters or the underscore.

  Read the article

• c# Why can't open generic types be passed as parameters?

  - by Rich Oliver

  Why can't open generic types be passed as parameters. I frequently have classes like: public class Example<T> where T: BaseClass { public int a {get; set;} public List<T> mylist {get; set;} } Lets say BaseClass is as follows; public BaseClass { public int num; } I then want a method of say: public int MyArbitarySumMethod(Example example)//This won't compile Example not closed { int sum = 0; foreach(BaseClass i in example.myList)//myList being infered as an IEnumerable sum += i.num; sum = sum * example.a; return sum; } I then have to write an interface just to pass this one class as a parameter as follows: public interface IExample { public int a {get; set;} public IEnumerable<BaseClass> myIEnum {get;} } The generic class then has to be modified to: public class Example<T>: IExample where T: BaseClass { public int a {get; set;} public List<T> mylist {get; set;} public IEnumerable<BaseClass> myIEnum {get {return myList;} } } That's a lot of ceremony for what I would have thought the compiler could infer. Even if something can't be changed I find it psychologically very helpful if I know the reasons / justifications for the absence of Syntax short cuts.

  Read the article

• what is the best algorithm to use for this problem

  - by slim

  Equilibrium index of a sequence is an index such that the sum of elements at lower indexes is equal to the sum of elements at higher indexes. For example, in a sequence A: A[0]=-7 A[1]=1 A[2]=5 A[3]=2 A[4]=-4 A[5]=3 A[6]=0 3 is an equilibrium index, because: A[0]+A[1]+A[2]=A[4]+A[5]+A[6] 6 is also an equilibrium index, because: A[0]+A[1]+A[2]+A[3]+A[4]+A[5]=0 (sum of zero elements is zero) 7 is not an equilibrium index, because it is not a valid index of sequence A. If you still have doubts, this is a precise definition: the integer k is an equilibrium index of a sequence if and only if and . Assume the sum of zero elements is equal zero. Write a function int equi(int[] A); that given a sequence, returns its equilibrium index (any) or -1 if no equilibrium indexes exist. Assume that the sequence may be very long.

  Read the article

• Trying to create fields based on a case statement

  - by dido

  I'm having some trouble with the query below. I am trying to determine if the "category" field is A, B or C and then creating a field based on the category. That field would sum up payments field. But I'm running into error saying "incorrect syntax near keyword As". I am creating this in a SQL View. Using SQL Server 2008 SELECT r.id, r.category CASE WHEN r.category = 'A' then SUM(r.payment) As A_payments WHEN r.category = 'B' then SUM(r.payment) As B_payments WHEN r.category = 'C' then SUM(r.payment) As C_payments END FROM r_invoiceTable As r GROUP BY r.id, r.category I have data where all of the above cases should be executed because the data that I have has A,B and C Sample Data- r_invoiceTable Id --- Category ---- Payment 222 A ---- 50 444 A ---- 30 111 B ---- 90 777 C ---- 20 555 C ---- 40 Desired Output A_payments = 80, B_payments = 90, C_payments = 60

  Read the article

• Is scala functional programming slower than traditional coding?

  - by Fred Haslam

  In one of my first attempts to create functional code, I ran into a performance issue. I started with a common task - multiply the elements of two arrays and sum up the results: var first:Array[Float] ... var second:Array[Float] ... var sum=0f; for(ix<-0 until first.length) sum += first(ix) * second(ix); Here is how I reformed the work: sum = first.zip(second).map{ case (a,b) => a*b }.reduceLeft(_+_) When I benchmarked the two approaches, the second method takes 40 times as long to complete! Why does the second method take so much longer? How can I reform the work to be both speed efficient and use functional programming style?

  Read the article

• Solving problems with near infinite potential solutions

  - by Zonda333

  Today I read the following problem: Use the digits 2, 0, 1, 1 and the operations +, -, x, ÷, sqrt, ^ , !, (), combinations, and permutations to write equations for the counting numbers 1 through 100. All four digits must be used in each expression. Only the digits 2, 0, 1, 1 may be used, and each must be used exactly once. Decimals may be used, as in .1, .02, etc. Digits may be combined; numbers such as 20 or 101 may be used. Example: 60 = 10*(2+1)!, 54 = ¹¹C2 - 0! Though I was able to quickly find around 50 solutions quite easily in my head, I thought programming it would be a far superior solution. However, I then realized I had no clue how to go about solving a problem like this. I am not asking for complete code for me to copy and paste, but for ideas about how I would solve this problems, and others like it that have nearly infinite potential solutions. As I will be writing it in python, where I have the most experience, I would prefer if the answers were more python based, but general ideas are great too.

  Read the article

• Is it possible to aggregate over differing where clauses?

  - by BenAlabaster

  Is it possible to calculate multiple aggregates based on differing where clauses? For instance: Let's say I have two tables, one for Invoice and one for InvoiceLineItems. The invoice table has a total field for the invoice total, and each of the invoice line item records in the InvoiceLineItems table contains a field that denotes whether the line item is discountable or not. I want three sum totals, one where Discountable = 0 and one where Discountable = 1 and one where Discountable is irrelevant. Such that my output would be: InvoiceNumber Total DiscountableTotal NonDiscountableTotal ------------- ----- ----------------- -------------------- 1 53.27 27.27 16.00 2 38.94 4.76 34.18 3... The only way I've found so far is by using something like: Select i.InvoiceNumber, i.Total, t0.Total As DiscountableTotal, t1.Total As NonDiscountableTotal From Invoices i Left Join ( Select InvoiceNumber, Sum(Amount), From InvoiceLineItems Where Discountable = 0 Group By InvoiceNumber ) As t0 On i.InvoiceNumber = t0.InvoiceNumber Left Join ( Select InvoiceNumber, Sum(Amount) From InvoiceLineItems Where Discountable = 1 Group By InvoiceNumber ) As t1 On i.InvoiceNumber = t1.InvoiceNumber This seems somewhat cumbersome, it would be nice if I could do something like: Select InvoiceNumber, Sum(Amount) Where Discountable = 1 As Discountable Sum(Amount) Where Discountable = 0 As NonDiscountable Group By InvoiceNumber I realize that SQL is completely invalid, but it logically portrays what I'm trying to do... TIA P.S. I need this to run on a SQL Server 2000 instance, but I am also interested (for future reference) if/how I would achieve this on SQL Server 2005/2008.

  Read the article

• Project Euler #119 Make Faster

  - by gangqinlaohu

  Trying to solve Project Euler problem 119: The number 512 is interesting because it is equal to the sum of its digits raised to some power: 5 + 1 + 2 = 8, and 8^3 = 512. Another example of a number with this property is 614656 = 28^4. We shall define an to be the nth term of this sequence and insist that a number must contain at least two digits to have a sum. You are given that a2 = 512 and a10 = 614656. Find a30. Question: Is there a more efficient way to find the answer than just checking every number until a30 is found? My Code int currentNum = 0; long value = 0; for (long a = 11; currentNum != 30; a++){ //maybe a++ is inefficient int test = Util.sumDigits(a); if (isPower(a, test)) { currentNum++; value = a; System.out.println(value + ":" + currentNum); } } System.out.println(value); isPower checks if a is a power of test. Util.sumDigits: public static int sumDigits(long n){ int sum = 0; String s = "" + n; while (!s.equals("")){ sum += Integer.parseInt("" + s.charAt(0)); s = s.substring(1); } return sum; } program has been running for about 30 minutes (might be overflow on the long). Output (so far): 81:1 512:2 2401:3 4913:4 5832:5 17576:6 19683:7 234256:8 390625:9 614656:10 1679616:11 17210368:12 34012224:13 52521875:14 60466176:15 205962976:16 612220032:17

  Read the article

• 3x3 Average filter in matlab

  - by turingcomplete

  I've written code to smooth an image using a 3x3 averaging filter, however the output is strange, it is almost all black. Here's my code. function [filtered_img] = average_filter(noisy_img) [m,n] = size(noisy_img); filtered_img = zeros(m,n); for i = 1:m-2 for j = 1:n-2 sum = 0; for k = i:i+2 for l = j:j+2 sum = sum+noisy_img(k,l); end end filtered_img(i+1,j+1) = sum/9.0; end end end I call the function as follows: img=imread('img.bmp'); filtered = average_filter(img); imshow(uint8(filtered)); I can't see anything wrong in the code logic so far, I'd appreciate it if someone can spot the problem.

  Read the article

< Previous Page | 24 25 26 27 28 29 30 31 32 33 34 35  | Next Page >