Fortran Fortran Program Doubt: Plotting DST Index Values

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The discussion revolves around a Fortran program intended to plot DST index values using PGPlot. The user encountered issues with incorrect plotting of data points despite successfully writing formatted output. The problem was traced back to the declaration of variables; specifically, the user had declared arrays as real while the data points were read as integers. It was highlighted that in Fortran, implicit variable types can lead to confusion, as variables beginning with certain letters are assumed to be floating-point unless explicitly declared otherwise. After receiving guidance on the correct data types and formats, the user resolved the issue by correcting the variable declarations, leading to successful plotting of the data.
agalya
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i have written a program to plot dst index values using fortran + pgplot, read the input as formatted input
when I'm trying to plot the data points are not plotted correctly.
k = 0
do i = isdt, iedt --------------start date to end date
do j = 1,24
k = k+1
x_val1(j) = x_val(i,j) ---------------------(a)
dst_val1(j) = dst_val(i,j) ----------------(b)
call pgdraw(x_val1(j),dst_val1(j))
enddo
c call pgline(k, x_val1,dst_val1)
c call pgpoint(k-1, x_val1,dst_val1,17)
write(*,'(f11.3,2x,i5)')(x_val1(j),dst_val1(j),j = 1,24) -------------------(c)
enddo
this is the routine to plot, in a & b I am converting the 2d array to 1d array which I am using to plot.
when i try to plot them it is not coming properly, but when I am trying to write the samething (in c), it is writing properly (formatted output). can somebody please help me to solve this problem
 
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Has dst_val1(j) been previously defined as an integer? The format assumes it to be an integer.
In Fortran, implicit variables beginning with A-H and O-Z are assumed floating point variables. Integers default to names beginning with I-N... unless of course if the IMPLICIT statement was executed.

If the program does not print properly, could you post some of the results, and also post what you expect to see?
 
hi
thank u for ur comment
I've declared the arrays as real
the data points are read as integers(because there is no floating value in the data file)
I've attached the program and the data file
please take a look at it
 

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I believe that's where the problem lies.
If you have declared a variable as real, you would have to read it in using a floating format. The data itself could very well be integer. The format could be f4.0 to read in a real.
You could confirm this by printing some values as soon as you read it in. The same goes for output (write).
 
hi
thank you for your help,
as you said, the problem was with the declaration only,
after correcting the program is okey now

regards
 
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