Search Results

Search found 6031 results on 242 pages for 'imaginary numbers'.

Page 201/242 | < Previous Page | 197 198 199 200 201 202 203 204 205 206 207 208  | Next Page >

• Password Cracking in 2010 and Beyond

  - by mttr

  I have looked a bit into cryptography and related matters during the last couple of days and am pretty confused by now. I have a question about password strength and am hoping that someone can clear up my confusion by sharing how they think through the following questions. I am becoming obsessed about these things, but need to spend my time otherwise :-) Let's assume we have an eight-digit password that consists of upper and lower-case alphabetic characters, numbers and common symbols. This means we have 8^96 ~= 7.2 quadrillion different possible passwords. As I understand there are at least two approaches to breaking this password. One is to try a brute-force attack where we try to guess each possible combination of characters. How many passwords can modern processors (in 2010, Core i7 Extreme for eg) guess per second (how many instructions does a single password guess take and why)? My guess would be that it takes a modern processor in the order of years to break such a password. Another approach would consist of obtaining a hash of my password as stored by operating systems and then search for collisions. Depending on the type of hash used, we might get the password a lot quicker than by the bruteforce attack. A number of questions about this: Is the assertion in the above sentence correct? How do I think about the time it takes to find collisions for MD4, MD5, etc. hashes? Where does my Snow Leopard store my password hash and what hashing algorithm does it use? And finally, regardless of the strength of file encryption using AES-128/256, the weak link is still my en/decryption password used. Even if breaking the ciphered text would take longer than the lifetime of the universe, a brute-force attack on my de/encryption password (guess password, then try to decrypt file, try next password...), might succeed a lot earlier than the end of the universe. Is that correct? I would be very grateful, if people could have mercy on me and help me think through these probably simple questions, so that I can get back to work.

  Read the article

• Problem with writing a hexadecimal string

  - by quilby

  Here is my code /* gcc -c -Wall -g main.c gcc -g -lm -o main main.o */ #include <stdlib.h> #include <stdio.h> #include <string.h> void stringToHex(const char* string, char* hex) { int i = 0; for(i = 0; i < strlen(string)/2; i++) { printf("s%x", string[2*i]); //for debugging sprintf(&hex[i], "%x", string[2*i]); printf("h%x\n", hex[i]); //for debugging } } void writeHex(char* hex, int length, FILE* file, long position) { fseek(file, position, SEEK_SET); fwrite(hex, sizeof(char), length, file); } int main(int argc, char** argv) { FILE* pic = fopen("hi.bmp", "w+b"); const char* string = "f2"; char hex[strlen(string)/2]; stringToHex(string, hex); writeHex(hex, strlen(string)/2, pic, 0); fclose(pic); return 0; } I want it to save the hexadecimal number 0xf2 to a file (later I will have to write bigger/longer numbers though). The program prints out - s66h36 And when I use hexedit to view the file I see the number '36' in it. Why is my code not working? Thanks!

  Read the article

• Radix Sort in Python [on hold]

  - by Steven Ramsey

  I could use some help. How would you write a program in python that implements a radix sort? Here is some info: A radix sort for base 10 integers is a based on sorting punch cards, but it turns out the sort is very ecient. The sort utilizes a main bin and 10 digit bins. Each bin acts like a queue and maintains its values in the order they arrive. The algorithm begins by placing each number in the main bin. Then it considers the ones digit for each value. The rst value is removed and placed in the digit bin corresponding to the ones digit. For example, 534 is placed in digit bin 4 and 662 is placed in the digit bin 2. Once all the values in the main bin are placed in the corresponding digit bin for ones, the values are collected from bin 0 to bin 9 (in that order) and placed back in the main bin. The process continues with the tens digit, the hundreds, and so on. After the last digit is processed, the main bin contains the values in order. Use randint, found in random, to create random integers from 1 to 100000. Use a list comphrension to create a list of varying sizes (10, 100, 1000, 10000, etc.). To use indexing to access the digits rst convert the integer to a string. For this sort to work, all numbers must have the same number of digits. To zero pad integers with leading zeros, use the string method str.zfill(). Once main bin is sorted, convert the strings back to integers. I'm not sure how to start this, Any help is appreciated. Thank you.

  Read the article

• How to map coordinates in AxesImage to coordinates in saved image file?

  - by Vebjorn Ljosa

  I use matplotlib to display a matrix of numbers as an image, attach labels along the axes, and save the plot to a PNG file. For the purpose of creating an HTML image map, I need to know the pixel coordinates in the PNG file for a region in the image being displayed by imshow. I have found an example of how to do this with a regular plot, but when I try to do the same with imshow, the mapping is not correct. Here is my code, which saves an image and attempts to print the pixel coordinates of the center of each square on the diagonal: import numpy as np import matplotlib.pyplot as plt fig = plt.figure() ax = fig.add_axes([0.1, 0.1, 0.8, 0.8]) axim = ax.imshow(np.random.random((27,27)), interpolation='nearest') for x, y in axim.get_transform().transform(zip(range(28), range(28))): print int(x), int(fig.get_figheight() * fig.get_dpi() - y) plt.savefig('foo.png', dpi=fig.get_dpi()) Here is the resulting foo.png, shown as a screenshot in order to include the rulers: The output of the script starts and ends as follows: 73 55 92 69 111 83 130 97 149 112 … 509 382 528 396 547 410 566 424 585 439 As you see, the y-coordinates are correct, but the x-coordinates are stretched: they range from 73 to 585 instead of the expected 135 to 506, and they are spaced 19 pixels o.c. instead of the expected 14. What am I doing wrong?

  Read the article

• Custom Calculations in a Matrix - Reporting Services 2005

  - by bfrancis

  I am writing a report to show gas usage (in gallons) used by each department. The request is to view each month and the gallons used by each department. A column is required to display what each departments target goal is, based on the gallons of gas they have used in a past time frame. Each departments target goal is x percent less than the total gallons used for said time frame. I currently have a matrix in Reporting Services with departments making up rows, months making up columns, and gallons filling the details. The matrix is being filled by dataset1. I have the data grouping as is requested for each month by each department. My problem is calculating the target goal. My thought was to create a second dataset (dataset2) that returns the gallons used based on the time frame requested. I grouped this data by department. I was hoping I could use the department field in each dataset to make sure the appropriate numbers were used. I added a new column which shows up next to the gallons field. As I attempted to build the Expression I found out that I could only grab the gallons used from dataset2 if I was summing the gallons field. This gives me the total gallons used by every department combined. I have tried to find resources with similar examples of what I am trying to accomplish but I cannot seem to come across one. I am trying to keep this as detailed as possible without making it too wordy. I would be more than happy to clarify or explain into further detail what I have written above if it is needed. If anyone has links, comments, or suggestions they would be greatly appreciated. A very simple visual or what I am hoping to accomplish is below. The months and departments would expand based on the data returned. months ------------------------------ departments| gallons/month | target goal

  Read the article

• Scale image to fit text boxes around borders

  - by nispio

  I have the following plot in Matlab: The image size may vary, and so may the length of the text boxes at the top and left. I dynamically determine the strings that go in these text boxes and then create them with: [M,N] = size(img); imagesc((1:N)-0.5,(1:M)-0.5, img > 0.5); axis image; grid on; colormap([1 1 1; 0.5 0.5 0.5]); set(gca,'XColor','k','YColor','k','TickDir','out') set(gca,'XTick',1:N,'XTickLabel',cell(1,N)) set(gca,'YTick',1:N,'YTickLabel',cell(1,N)) for iter = 1:M text(-0.5, iter-0.5, sprintf(strL, br{iter,:}), ... 'FontSize',16, ... 'HorizontalAlignment','right', ... 'VerticalAlignment','middle', ... 'Interpreter','latex' ); end for iter = 1:N text(iter-0.5, -0.5, {bc{:,iter}}, ... 'FontSize',16, ... 'HorizontalAlignment','center', ... 'VerticalAlignment','bottom', ... 'Interpreter','latex' ); end where br and bc are cell arrays containing the appropriate numbers for the labels. The problem is that most of the time, the text gets clipped by the edges of the figure. I am using this as a workaround: set(gca,'Position',[0.25 0.25 0.5 0.5]); As you can see, I am simply adding a larger border around the plot so that there is more room for the text. While this scaling works for one zoom level, if I maximize my plot window I get way too much empty space, and if I shrink my plot window, I get clipping again. Is there a more intelligent way to add these labels to use the minimum amount of space while making sure that the text does not get clipped?

  Read the article

• Plotting andrews curves of subsets of a data frame on the same plot

  - by user2976477

  I have a data frame of 12 columns and I want to plot andrews curves in R of this data, basing the color of the curves on the 12th columns. Below are a few samples from the data (sorry the columns are not aligned with the numbers) Teacher_explaining Teacher_enthusiastic Teacher_material_interesting Material_stimulating Material_useful Clear_marking Marking_fair Feedback_prompt Feedback_clarifies Detailed_comments Notes Year 80 80 80 80 85 85 80 80 80 80 70 3 70 60 30 40 70 60 30 40 70 0 30 3 100 90 90 80 80 100 100 90 100 100 100 MSc 85 85 85 90 90 70 90 50 70 80 100 MSc 90 50 90 90 90 70 100 50 80 100 100 4 100 80 80 75 90 80 80 50 80 80 90 3 From this data I tried to plot andrews curves using the code below: install.packages("andrews") library(andrews) col <- as.numeric(factor(course[,12])) andrews(course[,1:12], clr = 12) However, the 12th column has three groups (3 types of responses) and I want to group two of them and then plot the andrews curve of the data, without editing my data frame in Excel. x <- subset(course, Year == "MSc" & "4") y <- subset(course, Year == "3") I tried the above code, but my argument for x don't work. "MSc", "3" and "4" are the groups in the 12th column, and I want to group MSc and 4 so that their Andrews curves have the same color. If you have any idea how to do this, please let me know.

  Read the article

• Angularjs: addition of integers even after I parse the variable as integer

  - by Shiv Kumar

  I really have a weird problem in adding two numbers. Here is my code, in the first controller everything is working fine, but in the second controller instead of 0 if I add 10, the output is completely weird Here is html code <div ng-app=""> <div ng-controller="Controller1"> <br/>**** Controller-1 <br/>Add 0 : {{update1(0)}} <br/>Add 10 : {{update1(10)}} <br/>Add 50 : {{update1(50)}} <br/>Add -60 : {{update1(-60)}}</div> <div ng-controller="Controller2"> <br/>**** Controller-2 <br/>Add 10 : {{update2(10)}} <br/>Add 10 : {{update2(10)}} <br/>Add 50 : {{update2(50)}} <br/>Add -60 : {{update2(-60)}}</div> </div> Here is my javascript function Controller1($scope) { var x = 0; $scope.update1 = function (smValue) { x += parseInt(smValue); return x; } } function Controller2($scope) { var y = 0; $scope.update2 = function (smValue) { y += parseInt(smValue); return y; } } and here is the output **** Controller-1 Add 0 : 0 Add 10 : 10 Add 50 : 60 Add -60 : 0 **** Controller-2 Add 0 : 110 Add 10 : 120 Add 50 : 170 Add -60 : 110 here is the link to try: http://jsfiddle.net/6VqqN/ can anyone please explain me why it is behaving like that. Even if I add a 3or4 digit number, output is completely different then what I expected.

  Read the article

• How do you read a file line by line in your language of choice?

  - by Jon Ericson

  I got inspired to try out Haskell again based on a recent answer. My big block is that reading a file line by line (a task made simple in languages such as Perl) seems complicated in a functional language. How do you read a file line by line in your favorite language? So that we are comparing apples to other types of apples, please write a program that numbers the lines of the input file. So if your input is: Line the first. Next line. End of communication. The output would look like: 1 Line the first. 2 Next line. 3 End of communication. I will post my Haskell program as an example. Ken commented that this question does not specify how errors should be handled. I'm not overly concerned about it because: Most answers did the obvious thing and read from stdin and wrote to stdout. The nice thing is that it puts the onus on the user to redirect those streams the way they want. So if stdin is redirected from a non-existent file, the shell will take care of reporting the error, for instance. The question is more aimed at how a language does IO than how it handles exceptions. But if necessary error handling is missing in an answer, feel free to either edit the code to fix it or make a note in the comments.

  Read the article

• Mouse move panning

  - by Rudy

  Hi all, I'm trying to scroll a series of thumbnails horizontally based on the mouseX position. I can get it to scroll but it's very choppy and for some reason it's not reading my start and end numbers so it will stop scrolling. Can anyone point me in the right direction? Thanks. var thumbBounds:Object = new Object(); thumbBounds = thumbContainer.getBounds(this); thumbContainer.addEventListener(MouseEvent.MOUSE_OVER, setScrolling); private function setScrolling(me:MouseEvent):void { thumbContainer.removeEventListener(MouseEvent.MOUSE_OVER, setScrolling); stage.addEventListener(Event.ENTER_FRAME, scrollThumbs); } private function scrollThumbs(e:Event):void { if(mouseX <= thumbBounds.x || mouseX thumbBounds.width || mouseX < thumbBounds.y || mouseX thumbBounds.height) { thumbContainer.addEventListener(MouseEvent.MOUSE_OVER, setScrolling); stage.removeEventListener(Event.ENTER_FRAME, scrollThumbs); } if(thumbContainer.x = 0) { thumbContainer.x = 0; } if(thumbContainer.x <= -842) { thumbContainer.x = -842; } var xdist:Number = new Number(); xdist = mouseX - 382; thumbContainer.x += Math.round(-xdist / 10); }

  Read the article

• Why can't I build this Javascript object?

  - by Alex Mcp

  I have an object I'm trying to populate from another object (that is, iterate over a return object to produce an object with only selected values from the original). My code looks like this: var collect = {}; function getHistoricalData(username){ $.getJSON("http://url/" + username + ".json?params", function(data){ for (var i=0; i < data.length; i++) { console.log(i); collect = { i : {text : data[i].text}}; $("#wrap").append("<span>" + data[i].text + "</span><br />"); }; console.log(collect); }); } So I'm using Firebug for debugging, and here's what I know: The JSON object is intact console.log(i); is showing the numbers 1-20 as expected When I log the collect object at the end, it's structure is this: var collect = { i : {text : "the last iteration's text"}}; So the incrementer is "applying" to the data[i].text and returning the text value, but it's not doing what I expected, which is create a new member of the collect object; it's just overwriting collect.i 20 times and leaving me with the last value. Is there a different syntax I need to be using for assigning object members? I tried collect.i.text = and collect[i].text = and the error was that whatever I tried was undefined. I'd love to know what's going on here, so the more in-depth an explanation the better. Thanks!

  Read the article

• Google Maps Terms of Service - saving some data to a database

  - by R.M.

  I've read the terms of service, and, from what I understand, I'm not allowed to store any information I retrieve from the Google Maps API. Are there any exceptions to this? More to the point, I'm planning on building an application that shows the user several points of interest (like restaurants, libraries etc) at a certain distance around a location he chooses (it can be in one city or more, depending on the distance he chooses). There are two problems: The first problem is that (at least for my country) the geocoder doesn't locate exact addresses, at best it only locates street names (but completely ignores street numbers) in larger cities. It is even worse for smaller rural areas. So the only way to accurately show the places on the map is by storing their coordinates in the database. Another problem seems to be with calculating distances. To show the points located below a certain distance from the user, it would mean I would have to use GDirections to get all distances between the user's location and the other points, to see which ones to show. That would be really slow for the user (since I also have to set a small delay between requests), and it would also send a pretty large amount of requests to google. Would I be allowed to store those distances in a database? The users would not be able to access a list of all the stored information, they would only see the names of the places, and a map with some markers on it. Thank you.

  Read the article

• SQL Query with multiple values in one column

  - by lp1

  I've been beating my head on the desk tring to figure this one out. I have a table that stores job information, and reasons for a job not being completed. The reasons are numeric,01,02,03,etc. You can have two reason for a pending job. If you select two reasons, they are stored in the same column, seperated by a comma. This is anExample from the JOBID table: Job_Number User_Assigned PendingInfo 1 user1 01,02 Now, there is another table named Pending, that stores what those values actually represent. 01=Not enough info, 02=Not enough time, 03=Waiting Review. Example: Pending_Num PendingWord 01 Not Enough Info 02 Not Enough Time What I'm trying to do is query the database to give me all the job numbers, users, pendinginfo, and pending reason. I can break out the first value, but can't figure out how to do the second. What my limited skills have so far: *select Job_number,user_assigned,SUBSTRING(pendinginfo,0,3),pendingword from jobid,pending where SUBSTRING(pendinginfo,0,3)=pending.pending_num and pendinginfo!='00,00' and pendinginfo!='NULL'* What I would like to see for this example would be: Job_Number User_Assigned PendingInfo PendingWord PendingInfo PendingWord 1 User1 01 Not Enough Info 02 Not Enough Time Thanks in advance

  Read the article

• calling .ajax() from an eventHandler c# asp.ent

  - by ibininja

  Good day...! In the code behind (upload.aspx) I have an event that returns the number of bytes being streamed; and as I debug it, it works fine. I wanted to reflect the numbers returned from the eventHandler on a progress bar and this is where I got lost. I tried using jQuery's .ajax() function. this is how I implemented it: In the EventHandler in my code behind I added this code to call the .ajax() function: Page.ClientScript.RegisterStartupScript(this.GetType(), "UpdateProgress", "<script type='text/javascript'>updateProgress();</script>"); My plan is whenever the eventHandler function changes the values of bytes being streamed it calls the javascript function "updateProgress()" The .ajax() function "UpdateProgress()" is as: function updateProgress() { $.ajax({ type: "POST", url: "upload.aspx/GetData", data: "{}", contentType: "application/json; charset=utf-8", dataType: "json", async: true, success: function (msg) { $("#progressbar").progressbar("option", "value", msg.d); } }); } I made sure that the function GetData() is [System.Web.Services.WebMethod] and that it is static as well. so the workflow of what I am trying to implement is as: - Click On Upload button - The Behind code starts executing and EventHandler triggers - The EventHandler calls .ajax() function - The .ajax() function retrieves the bytes being streamed and updates progress bar. When I ran the code; all runs well except that the .ajax() is only executed when upload is finished (and progress bar also updates only when finished upload); even though I call .ajax() function every time in the eventHandler function as reflected above... What am I doing wrong? Am I thinking of this right? is there anything else I should add maybe an updatePanel or something? thank you

  Read the article

• How do I define a Calculated Measure in MDX based on a Dimension Attribute?

  - by ShaneD

  I would like to create a calculated measure that sums up only a specific subset of records in my fact table based on a dimension attribute. Given: Dimension Date LedgerLineItem {Charge, Payment, Write-Off, Copay, Credit} Measures LedgerAmount Relationships * LedgerLineItem is a degenerate dimension of FactLedger If I break down LedgerAmount by LedgerLineItem.Type I can easily see how much is charged, paid, credit, etc, but when I do not break it down by LedgerLineItem.Type I cannot easily add the credit, paid, credit, etc into a pivot table. I would like to create separate calculated measures that sum only specific type (or multiple types) of ledger facts. An example of the desired output would be: | Year | Charged | Total Paid | Amount - Ledger | | 2008 | $1000 | $600 | -$400 | | 2009 | $2000 | $1500 | -$500 | | Total | $3000 | $2100 | -$900 | I have tried to create the calculated measure a couple of ways and each one works in some circumstances but not in others. Now before anyone says do this in ETL, I have already done it in ETL and it works just fine. What I am trying to do as part of learning to understand MDX better is to figure out how to duplicate what I have done in the ETL in MDX as so far I am unable to do that. Here are two attempts I have made and the problems with them. This works only when ledger type is in the pivot table. It returns the correct amount of the ledger entries (although in this case it is identical to [amount - ledger] but when I try to remove type and just get the sum of all ledger entries it returns unknown. CASE WHEN ([Ledger].[Type].currentMember = [Ledger].[Type].&[Credit]) OR ([Ledger].[Type].currentMember = [Ledger].[Type].&[Paid]) OR ([Ledger].[Type].currentMember = [Ledger].[Type].&[Held Money: Copay]) THEN [Measures].[Amount - ledger] ELSE 0 END This works only when ledger type is not in the pivot table. It always returns the total payment amount, which is incorrect when I am slicing by type as I would only expect to see the credit portion under credit, the paid portion, under paid, $0 under charge, etc. sum({([Ledger].[Type].&[Credit]), ([Ledger].[Type].&[Paid]), ([Ledger].[Type].&[Held Money: Copay])}, [Measures].[Amount - ledger]) Is there any way to make this return the correct numbers regardless of whether Ledger.Type is included in my pivot table or not?

  Read the article

• Checking inherited attributes in an 'ancestry' based SQL table

  - by Brendon Muir

  I'm using the ancestry gem to help organise my app's tree structure in the database. It basically writes a childs ancestor information to a special column called 'ancestry'. The ancestry column for a particular child might look like '1/34/87' where the parent of this child is 87, and then 87's parent is 34 and 34's is 1. It seems possible that we could select rows from this table each with a subquery that checks all the ancestors to see if a certain attribute it set. E.g. in my app you can hide an item and its children just by setting the parent element's visibility column to 0. I want to be able to find all the items where none of their ancestors are hidden. I tried converting the slashes to comma's with the REPLACE command but IN required a set of comma separated integers rather than one string with comma separated string numbers. It's funny, because I can do this query in two steps, e.g. retrieve the row, then take its ancestry column, split out the id's and make another query that checks that the id is IN that set of id's and that visibility isn't ever 0 and whala! But joining these into one query seems to be quite a task. Much searching has shown a few answers but none really do what I want. SELECT * FROM t1 WHERE id = 99; 99's ancestry column reads '1/34/87' SELECT * FROM t1 WHERE visibility = 0 AND id IN (1,34,87); kind of backwards, but if this returns no rows then the item is visible. Has anyone come across this before and come up with a solution. I don't really want to go the stored procedure route. It's for a rails app.

  Read the article

• How to convert struct to char array in C

  - by falcojr

  I'm trying to convert a struct to a char array to send over the network. However, I get some weird output from the char array when I do. #include <stdio.h> struct x { int x; } __attribute__((packed)); int main() { struct x a; a.x=127; char *b = (char *)&a; int i; for (i=0; i<4; i++) printf("%02x ", b[i]); printf("\n"); for (i=0; i<4; i++) printf("%d ", b[i]); printf("\n"); return 0; } Here is the output for various values of a.x (on an X86 using gcc): 127: 7f 00 00 00 127 0 0 0 128: ffffff80 00 00 00 -128 0 0 0 255: ffffffff 00 00 00 -1 0 0 0 256: 00 01 00 00 0 1 0 0 I understand the values for 127 and 256, but why do the numbers change when going to 128? Why wouldn't it just be: 80 00 00 00 128 0 0 0 Am I forgetting to do something in the conversion process or am I forgetting something about integer representation? *Note: This is just a small test program. In a real program I have more in the struct, better variable names, and I convert to little-endian. *Edit: formatting

  Read the article

• Is there stl and utf8 friendly C++ Wrapper for ICU, or other powerful unicode library

  - by artyom

  Hello, I need a good Unicode library for C++. I need Transformations in Unicode sensitive way. For example sort all strings in case insensitive way and get their first characters for index. Convert to upper and to lower various Unicode strings. Split text in reasonable position -- words that would work for Chinese and Japanese as well. Formatting numbers, dates in locale sensitive way (should be thread safe). Transparent support of utf8 (primary internal representation). As far as I know the best library is ICU. However, I can't find normal developer friendly API documentation with examples. Also as far as I see, it is not too friendly with modern C++ design, work with STL and so on. Like this std::string msg; unistring umsg.from_utf8(msg); unistring::word_iterator wi; for(wi=umsg.words().begin(),n=0;wi!=usmg.words().wi_end(),n<10;++wi,++n) ; msg=umsg.substr(umsg.words().begin(),wi).to_utf8(); cout<<_("Five 10 words are ")<<msg; Does anybody know good STL friendly ICU wrapper released under Open Source license preferred permissive like MIT or Boost, but others LGPLv2 compatible are ok as well. Is there another high quality library similar to ICU? Platform: UNIX/POSIX, Windows support is not required. Thanks, Artyom Edit: Unfortunatly I wasn't logged in so I can't make asnver accepted... I had attached the ansver by myself.

  Read the article

• 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; }

  Read the article

• Payment Processors - What do I need to know if I want to accept credit cards on my website?

  - by Michael Pryor

  This question talks about different payment processors and what they cost, but I'm looking for the answer to what do I need to do if I want to accept credit card payments? Assume I need to store credit card numbers for customers, so that the obvious solution of relying on the credit card processor to do the heavy lifting is not available. PCI Data Security, which is apparently the standard for storing credit card info, has a bunch of general requirements, but how does one implement them? And what about the vendors, like Visa, who have their own best practices? Do I need to have keyfob access to the machine? What about physically protecting it from hackers in the building? Or even what if someone got their hands on the backup files with the sql server data files on it? What about backups? Are there other physical copies of that data around? Tip: If you get a merchant account, you should negotiate that they charge you "interchange-plus" instead of tiered pricing. With tiered pricing, they will charge you different rates based on what type of Visa/MC is used -- ie. they charge you more for cards with big rewards attached to them. Interchange plus billing means you only pay the processor what Visa/MC charges them, plus a flat fee. (Amex and Discover charge their own rates directly to merchants, so this doesn't apply to those cards. You'll find Amex rates to be in the 3% range and Discover could be as low as 1%. Visa/MC is in the 2% range). This service is supposed to do the negotiation for you (I haven't used it, this is not an ad, and I'm not affiliated with the website, but this service is greatly needed.) This blog post gives a complete rundown of handling credit cards (specifically for the UK).

  Read the article

• Load Spikes on a Apache MySQL Server with Wordpress MU

  - by Vikram Goyal

  Hi there, I am trying to investigate the reasons for some mysterious load spikes on a Linux Apache server (2.2.14) running PHP 5.2.9 on a dedicated server with enough processing power and memory. My primary web application is a Wordpress MU (2.9.2) installation. I have investigated and ruled out DOS attack, MySQL or Apache configuration issues. The log files don't give me anything of interest, except to tell me that there is severe load. The load (which can go up to 100) just seems to come and go. It helps that I have a script that checks every 3 minutes for the load, and restarts Apache. Restarting it helps, and the server comes back, till it happens again. There seems to be no set time frame, or visitor numbers on the site that can trigger this. Even a low number of concurrent visitors (20) can trigger it. I am almost convinced that there is a rewrite loop somewhere that is causing Apache to go mad. Apache is trying to serve something that is causing it to spawn more and more processes till it keels over. My question is: Given that I am convinced that this is a rewrite issue or something similar, how can I try and figure out what the issue is? What should I monitor? Apache logs are voluminous, and not very helpful. Of course, if this is not the issue, then at least knowing what to look for will help me eliminate this as an issue and look for something else. Thanks! Vikram

  Read the article

• changing default my.cnf path in mysql

  - by user377941

  I am having two mysql instances on same machine. The installations are on /usr/loca/mysql1 and /usr/local/mysql2. I m having separate my.cnf files located in /etc/mysql1 and /etc/mysql2. I installed the first instance of my sql using source distribution and with the --prefix=/usr/local/mysql1 option. The second one i got from copying and pastinf the same directory to /usr/local/mysql2. When i start the mysql daemon on /usr.local/mysql/libexec it reads the my.cnf file in /etc/mysql1. And if i start the mysql daemon in /usr/local/mysql2 it reads the same my.cnf file. I have separate port numbers and .sock files defined in the .cnf file in those 2 locations. I can read the my.cnf file in the second location by using --defaults-file=/etc/mysql2/my.cnf option on mysqld startup. I dnt need to enter this each and every time i start the daemon. If i am going to have more instances how can i point the correct my.cnf file to read to each and every mysql daemon. What is the retionale behind mysqld links with the my.cnf file. how can i predefine the location of my.cnf file for each instance.

  Read the article

• How can I search an XML file without a dynamic language?

  - by jeph perro

  Let me try to explain my situation: We are using a CMS which 'bakes' a website, and you publish it to a webserver. The published site contains only static HTML ( or XML ) pages ( generated from the content in the CMS database ). I imported an XML file with the names and phone numbers from the company phone directory. Using only XSLT, can I create a way to search that directory? For example, if my XML file, directory.xml looks like this: <directory> <person> <fname>Ryan</fname> <lname>Purple</lname> <phone>887 778 5544</phone> </person> <person> <fname>Tanya</fname> <lname>Orange</lname> <phone>887 998 5541</phone> </person> <directory> Can I create a way to search for a person with the last name starting with "Pur" ? Can I pass a parameter to the XSLT? Can I search the XML tree to match the string in the parameter?

  Read the article

• Generating lognormally distributed random number from mean, coeff of variation

  - by Richie Cotton

  Most functions for generating lognormally distributed random numbers take the mean and standard deviation of the associated normal distribution as parameters. My problem is that I only know the mean and the coefficient of variation of the lognormal distribution. It is reasonably straight forward to derive the parameters I need for the standard functions from what I have: If mu and sigma are the mean and standard deviation of the associated normal distribution, we know that coeffOfVar^2 = variance / mean^2 = (exp(sigma^2) - 1) * exp(2*mu + sigma^2) / exp(mu + sigma^2/2)^2 = exp(sigma^2) - 1 We can rearrange this to sigma = sqrt(log(coeffOfVar^2 + 1)) We also know that mean = exp(mu + sigma^2/2) This rearranges to mu = log(mean) - sigma^2/2 Here's my R implementation rlnorm0 <- function(mean, coeffOfVar, n = 1e6) { sigma <- sqrt(log(coeffOfVar^2 + 1)) mu <- log(mean) - sigma^2 / 2 rlnorm(n, mu, sigma) } It works okay for small coefficients of variation r1 <- rlnorm0(2, 0.5) mean(r1) # 2.000095 sd(r1) / mean(r1) # 0.4998437 But not for larger values r2 <- rlnorm0(2, 50) mean(r2) # 2.048509 sd(r2) / mean(r2) # 68.55871 To check that it wasn't an R-specific issue, I reimplemented it in MATLAB. (Uses stats toolbox.) function y = lognrnd0(mean, coeffOfVar, sizeOut) if nargin < 3 || isempty(sizeOut) sizeOut = [1e6 1]; end sigma = sqrt(log(coeffOfVar.^2 + 1)); mu = log(mean) - sigma.^2 ./ 2; y = lognrnd(mu, sigma, sizeOut); end r1 = lognrnd0(2, 0.5); mean(r1) % 2.0013 std(r1) ./ mean(r1) % 0.5008 r2 = lognrnd0(2, 50); mean(r2) % 1.9611 std(r2) ./ mean(r2) % 22.61 Same problem. The question is, why is this happening? Is it just that the standard deviation is not robust when the variation is that wide? Or have a screwed up somewhere?

  Read the article

• I'm trying to use a regular expression to retrieve text from RichTextBox

  - by Simon

  Hello! As the header is implying I'm trying to retrieve a certain line of numbers from a richtextbox and then put it into a separate textbox. I've tried this code below but it doesn't wanna work with me. It's probably way wrong and there's probably easier ways of doing it but I'm quite new to this stuff and I would appreciate all the help I can get in this matter. I have a textbox called tbPersNr; A RichTextBox called tbText; A button which is called btnGet; string regPattern = @"\\d{6}-\\d{4}"; int indexOfSearch = 0; private void btnGet_Click(object sender, EventArgs e) { int startIndex = 0; if (tbText.Text.Length > 0) { startIndex = HittaPersNr(regPattern, startIndex, tbText.Text.Length); } if (startIndex > 0) { this.tbPersNr.Text = regPattern.ToString(); } } public int HittaPersNr(string txtToSearch, int searchStart, int searchEnd) { // Setting default value to -1. int retVal = -1; // Validating start of the search // om indexOfSearch = -1, slutar sökningen if (searchStart >= 0 && indexOfSearch >= 0) { // Validating end of search if (searchEnd > searchStart || searchEnd == -1) { // Searching for results in richtextbox indexOfSearch = tbText.Find(regPattern, searchStart, searchEnd, RichTextBoxFinds.None); // Validating if search resulted in any finds. if (indexOfSearch != -1) { // putting index to value in the text. retVal = indexOfSearch; } } } return retVal; } } } Cheers

  Read the article

< Previous Page | 197 198 199 200 201 202 203 204 205 206 207 208  | Next Page >