Optimizing Division/exponential Calculation?
Apr 15, 2010
I've inherited a Visual Studio/VB.Net numerical simulation project that has a likely inefficient calculation. Profiling indicates that the function is called a lot (1 million times plus) and spends about 50% of the overall calculation within this function. Here is the problematic portion
Result = (A * (E ^ C)) / (D ^ C * B) (where A-C are local double variables and D & E global double variables)
Result is then compared to a threshold which might have additional improvements as well, but I'll leave them another day
View 4 Replies
ADVERTISEMENT
Oct 6, 2011
I have a double type variable Sum and more than 1 textbox. When i divide one textbox value to another textbox value i got result of this type .00000000438000 and assign this value to another textbox. I want to change this value into exponentional form like 4.3*10-9. In which way i will change this value. I m trying my best effort bt i can't do this.
View 1 Replies
Feb 17, 2009
In a loop, i'm looking to add 1 to Var1's value everytime the loop goes.I've tried
[Code]...
View 1 Replies
Dec 19, 2009
I need to store a calculation to use later and obtain a new calculation
[Code]...
View 4 Replies
Aug 11, 2010
I'm building a GUI that displays a lot of thumbnails. I'm currently using PictureBoxes that I dynamically allocate to do this. In the worst case I may need to display as much as 1000 of these thumbnails at once. I need the thumbnails to move around and animate fluidly. PictureBoxes hog a lot of memory.
View 16 Replies
Apr 27, 2009
I have a function which is executed a lot of time during a flat file (txt) import. (50 000+)using a profiling tool the attached function where identified as 40% of the runtime..The code works as is.. But should be a lot quicker..
The code converts the following format 5710.436' N to the double representation.
DMS -> DD
MS Degrees:Minutes:Seconds (4930'00"N, 12330'00"W)
[code]....
View 3 Replies
Aug 10, 2009
I am using SQl data reader to get value from SQL database.Language VB.NET.After getting data into reader, i run a while loop
While reader.Read
If reader.HasRows() Then
/* Proessing of data *[code]....
View 3 Replies
Nov 11, 2011
I'm working on a FTP Client, I started loading the local directories of my PC. I'm a university student of Computer Science. I had problems with my code, because it takes approximately 35 seconds to load all the directories and sub directories to a TreeView that in the future I will use to navigate thru my computer folders and pass files & olders to the FTP.
Option Strict On
Option Explicit On
Imports System.Collections.ObjectModel
[code].....
View 3 Replies
Apr 8, 2010
I have a lengthy query..always it shows timeout..I am filling it in a dataset, not using command execute.Is there anyway to solve this rather than optimizing the code? any way to solve the timeout..
View 3 Replies
Apr 6, 2011
I'm having a speed issue with some drawing in a program I am working on. I have narrowed down the speed issues to a single function. The cost of this function is such that I really need to find a way to make it faster, and that should be possible.
The function is this:
Public Shared Sub SuperImposeFishAni(ByVal bckGrnd As Drawing.Bitmap, ByVal dtop As Integer, ByVal dleft As Integer, ByVal dwidth As Integer, ByVal dheight As Integer, ByVal ImageInQuestion As FishImages)
Dim tp As Integer = 0
[code]....
This is actually a holdover from an earlier design that included animation, but that's probably irrelevant. What is happening here is that a bitmap (bckGrnd) is passed to the method along with the left, top, width, and height that are to be drawn, and a single variable to select which image to draw.The image to draw is chosen in the select statement, which makes up the bulk of the method. The guts of the issue are the last few lines.
Through profiling, I was able to determine that if this method is called, the drawing takes over .25 seconds, whereas if this method is not called the same exact drawing takes less than .07 seconds. Therefore, I am getting a significant slowdown from this one method, which surprises me, as it is pretty straightforward. It pretty much has to be this method, too, because I can perform the same actions with or without this method being called. It is called if a Boolean is True, which is about as fast a test as can be performed. If the Boolean is False, this method is not called. The >3x difference in timing is with or without this method.
The point behind the method is that the image from the select statement has to be superimposed onto the background image, and the size of the area, as well as the location, that it gets superimposed onto is almost totally arbitrary, which is why the size and location has to passed to the method.Technically, choosing the bitmap to merge in (the select statement), could be avoided, but I doubt that is the issue.
View 21 Replies
Sep 9, 2011
I have this code that works. it goes down a range and deletes the empty rows, seperates the first character into a different column if its not a number or negative sign.This code WORKS. but it is too SLOW for the amount of data i need it to deal with. I have already turned off automatic calculations. screen updating.and visibility of application.
[Code]...
View 3 Replies
Sep 8, 2010
I have code that increments an array of numbers. However, due to performance issues, I need to optimize it.
Here is the code:
Public Sub increment(ByRef Index() As UInt16)
Dim N As Integer = Index.Length - 1
If (Index(0) = 65535) Then
Index(0) = 0
[Code] .....
View 18 Replies
Dec 28, 2011
I have this code that works. it goes down a range and deletes the empty rows, seperates the first character into a different column if its not a number or negative sign
View 1 Replies
Aug 4, 2009
As I was starting on my lil project i realized that I would have a tonne of repetitive code. But wasn't sure how best to go around to just only have it in there once and just call on it. Not entirely sure how to do this as I havnt done it before, I was trying to mess around with it in a Function type thing but I had declaration issues which put me off course. Basically they'll be a few labels lbl8Beats(on click it loads the table in the datagrid (dgvCompositions)) is the first, and all the code from Dim conn As MySqlConnection to data = New DataTable, will be repeated.When i was messing around and thought I'd open the connection on form load, and I just had a bunch of declaration issues, and was unsure how best to go about this. Also since the Adapter = "would be changing on each label it just made me more confused.[code]
View 1 Replies
Sep 8, 2009
I'm working on a function to return a exponential average and there are a lot of examples of exponential moving averages but they all start with a moving average that is just the mean as a lead in to calculating the continuing moving average. I needed just a exponential average of a value set. After Googling my Bing off I still haven't seen anything so here is my attempt at a basic exponential average. Is this correct? Are there any errors? I have seen some text about adding a smoothing value to change the curve of the exponential average but not how that would be implemented.
[Code]...
View 5 Replies
Feb 4, 2011
below is a byte array to string encoder. It uses the yEnc algorithm that is used for Usenet binaries (Usenet only supports text).
Doing a performance analysis in VS2010 shows that this is the most CPU intensive part of the application.
The encoder function is used thousands of times, so I'd like to optimize it as much as possible.
I'm using 'ReDim Preserve' instead of 'Take()ToArray', because I'm targeting .NET Framework 2.0. Is there a more efficient way of getting only a part of a byte array?
vb.net
'Values for yEnc Encoder
Public Structure EncoderValues
Public lChar As Byte
[Code].....
View 15 Replies
Aug 1, 2008
I'm developing a VB.Net 2008 application which uses background images (in jpg format) in some forms and controls, but this makes the application to use a lot of ram. My question is how to make it to use the less possible.
View 3 Replies
Dec 3, 2010
What's the difference between / and for division in vb.net? My code gives very different answers depending on which I use. I've seen both before, but never knew the difference.
View 3 Replies
Feb 24, 2011
I am using oledbconnection object with access database engine 64 bit to get data from Excel file. While using sqlconnection object if sql string has these statements "SET ARITHABORT OFF;SET ANSI_WARNINGS OFF;" , then division by zero exception doesn't cause any problem. But while using oledbconnection these statements cause error. My code samples are below:
Dim PbpConn As OleDbConnection = New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;" & _
"Data Source=C:BuzBeatDataPBPData.xls" & ";" & _
[Code]....
When SUM(pbA) has value "0" then it causes error and can't get data. is there a way to close the warnings and division by zero exceptions?
View 6 Replies
Sep 3, 2009
i face a problem while i practice the question in my text book, it require us to key in 4 digit of number and split it into 4 digit and encrypt it. Below is my coding [code] Console.WriteLine("The encrypted number is: " & encrypNumber3 & encrypNumber2 & encrypNumber1 & encrypNumber4)But its got error after i key in the 4 number.
View 2 Replies
Nov 16, 2010
I've got a problem approximating the result of a division that should give a sharp result:
I use this code:
pListPrice *= 100 / (100 + VATPercentage)
where VATPercentage = 20D is declared as Decimal type. pListPrice = 25.2D is declared Decimal too.
The result should be: 21.00 sharp!
Instead I get 20.99999999999999999999D
View 8 Replies
Feb 11, 2012
I have a group of 25 labels named Label1, Label2, Label3, ... Label25 in a square of 5 per row, 5 per column and I wanted to assign the backcolor to all of them on a loop and assign a value of "True" or "False" to a matrix of 25 boolean values representing them.
But I was getting errors on the pattern created.
My approach was to use a substring containing a number copied from the label names:
Num = Val(sender.name.substring(5))
And the subindexes of the matrix:
p = (Num - 1) / 5
q = (Num - 1) Mod 5
The values for the lower corner of the matrix were rouded to 5 instead of being 4. Instead of (4,0) ,(4,1), (4,2), (4,3) (4,4) I was getting (5,0),(5,1)...(5,5)
So I solved the problem by creating two single variables "A" and "B", doing the divission and MOD operations on them, finding the floor of them and then converting to integer:
Private Sub Label1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles _
Label1.Click, Label2.Click, Label3.Click, Label4.Click, Label5.Click, _
[Code]......
View 3 Replies
Dec 18, 2010
Deviding an int by zero, will throw an exception, but a float won't - at least in Java. Why a float have an additional NaN info, while int haven't?
View 6 Replies
Nov 29, 2010
i have got a value in time span lets say: tsp1= 2 hour 5 minuts i have a another time span variable which contains value like: tsp2= 0 hours , 2 minuts?how can i divide tsp1 by tsp2 so than i can get exact number of times tsp2 divied the tsp1 and how much value is remaining.i am using vs2008?
View 3 Replies
Apr 27, 2011
In the following linq query I have a division by zero exception wich I can't seem to code around. It occurs when the Sum of fldDevider returns 0.[code]...
How can I Make sure the ValuePerMonth field is 0 when the Group.Sum(Function(dr) CDec(dr.Field(Of String)(fldDevider))) function returns a 0. Or how do I return a 1 for Sum fldDevider if it is actually 0.
View 1 Replies
Mar 9, 2009
I have hit a block and not sure the best way to go with this. Looking for resources to find more on the subject
View 1 Replies
Mar 6, 2005
This exercise says :"Write a program that inputs one number consisting of five digits from the user, separates the number into its individual digits and prints the digits separated from one another by three spaces each. For example, if the user types the number 42339, the program should print
4 2 3 3 9 Use the command window for input and output. [Hint: This exercise is possible with the techniques discussed in this chapter. You will need to use both division and modulous operations go "pick off" each digit.]"
Here is what I have learned in Chapter 3:
�If/Then Statements
�Console.Write()
�Console.WriteLine()
[Code]....
This exercise I have yet to start, and don't think I will be able to do much, because I have no clue how to "Pick off" the numbers using division and modulous operators. I know what the mod operator does, but I do not know how to use it and division to do what this exercise is asking me to do.
View 10 Replies
Feb 17, 2012
How do you check if the division of two integers is a whole number, just answer with code, no links?
View 6 Replies
Jan 11, 2012
i'm just a begginer in using visual basic. i'm trying to add, subtract, multiply and divide two numbers. here is my code;[code]an error is occuring when i'm not putting any number on the textbox. now for the problem when i put a number to textbox1, and 0 to textbox2, there is also an error. It's because we can't divide a number to zero.
View 12 Replies
May 16, 2012
I am trying to load a small decimal number (eg 0.0566897 from a dataset field in to a variable (double), divide it by 2 and place it back in the dataset. After the divison, the variable is 0.0 and the rest of the decimal places are gone. How can I avoid losing the decimal places?
Dim dblCostps As Double = "0.0000000"
dblCostps = todds.Tables("todinfo").Rows(1).Item("cost_per_second")
dblCostps = dblCostps \ 2
todds.Tables("todinfo").Rows(1).Item("cost_per_second") = dblCostps
View 3 Replies
