a file and basic maths

[iknorr]

Im in the middle of writing a program. Part of that prog is to open a .txt file . The format of the file is two colums of numbers seperated by a comma i.e. row one would look like 0.23657, -3.6548,

approximately 3000 rows will be in the file.

I need to read in the data from the file, perform some maths and output the result.

Something like get the average of column 1 and the average from column 2 and add these results together.

Any ideas or source code?

Many thanx, Paul...

[chemicalNova]

I would use a 2 dimensional array, and a principal like pixels.
Eg:

Dim tTable(1, 2999) As String 'might take a while to load
              'X   'Y
Dim inptLine As String 'the input
Open "C:\test.txt" For Input As #1
Do While Not EOF(1)
    Input #1, inptLine
    For i = 0 To 2999
        For j = 0 To 1
            tTable(j, i) = inptLine
        Next j
    Next i
Loop
Close #1

Then you could use something like:

Dim avg As Double
For i = 0 To 2999
    avg = avg + tTable(0, i)
Next i
avg = (avg / 2999)

Unfortunately, if you are using text files, there won't be a quick way for this..

Phreak

[jeroen79]

You can split the lines with Output = Split(Input, Delimiter).
Output will be an array.

IIRC, when converting strings to numbers VB uses "," as the decimal separator.
You can replace the "." with Output = Replace(Input, ToReplace, ReplaceWith).

[chemicalNova]

But why split?

Visual Basic automatically delimits by commas, and since thats how the file is layed out, 1 input statement would input everything up to either a new line character, or a comma (,).

Phreak

[iknorr]

Im gonna try The "phreak" code.
Just one thing..... tTable is just like a 2d array, yes?

[Frans C]

IIRC, when converting strings to numbers VB uses "," as the decimal separator.
You can replace the "." with Output = Replace(Input, ToReplace, ReplaceWith).

When converting strings to numbers, VB will use the seperator that is defined in your regional settings.

[iknorr]

i just realised that the above code wont work the way i want it to.

i need to have both the variables in the row to be read in together. i.e. i need to have the x and y values of row one etc at the same time. (part of my formula needs to ultiply the x and y value of a row together. then acculmulate them.) (i know how to do the maths...i just need the two variables read together)
i know i can do this with ttable but it will require at least another loop. id like to do the calculations as the data is being read, in the same loop.

[jeroen79]

You could do two Inputs each time it goes through the loop and send the result of each Inout to a different variable.

[iknorr]

so how do i do that?
(and bty the number of rows will be approx 3000 but the exact number in the file will be unknown)

[iknorr]

ok all i got it sorted...... heres the portion of code im using to do that....its a bit messy but its does the job nicely..... (i added in a few RTB's for trouble shooting)
ill be adding in my maths later.
it also is much quicker than i thought. reads in 6000 values via 2 loops and displays them in 2 seconds on a p3.

Private Sub Command3_Click()
 Open "C:\Documents and Settings\paul.cullen\Desktop\log.txt" For Input As #1
 
 
    While Not EOF(1)
 
        Line Input #1, temp$               'read in one line at a time, and put in temp$
        alltext$ = alltext$ & temp$ & (Chr(13)) 'append to alltext$ with line feed. (just for trouble shooting)
 
    
        For I = 1 To Len(temp$) - 1 'the minus one is so that the loop will not read the second comma in the file and repeat for no reason.
                                     
            y = Mid(temp$, I, 1)       'checking for comma
            'n = n + 1                  'acculuminating number of characters before comma is reached
            If y = "," Then             'check for commas
               x$ = Left(temp$, I - 1)  ' at the first comma, this copies all the characters from the left to x$
               allx = allx & x$ & (Chr(13)) '(just for trouble shooting)
               ys$ = Right(temp$, Len(temp$) - I) ' taking all the characters to the right of the comma
               ys$ = Left(ys$, Len(temp$) - I - 1) ' removeing the comma at the end of the "y" data
               ally = ally & ys$ & (Chr(13)) '(just for trouble shooting)
            End If
            
        Next
    Wend
    RichTextBox1 = alltext$ 'temp read viewer. all RTB'sare for troubleshooting purposes.....removes them as needed.
    RichTextBox2 = ally       
    RichTextBox3 = allx
 
Close #1
End Sub

[jeroen79]

How about:

Input #1, A
  Input #1, B
  DoStuff (A, B)

And if want to split a Line Input result on the comma then Split() would be easier.

[iknorr]

looks nice (and way easier)but iv it done my way now. i had to do this for a couple of files so im not gonna change it now but thanks for the help anyway. im sure ill use it in future programming.