[Gnuplot-bugs] Problem of Interpretation

[<r....@ma...>]

Hi Team,

I write you let you know that Gnuplot seems to have a problem of  
interpreting mathematical expressions.

Here is the version used: Version 4.0 patchlevel 0, last modified Thu  
Apr 15 14:44:22 CEST 2004 (System: Darwin 8.6.0) Hereafter, both two  
equations (as per the plot command line) are identical but written in  
the different way.

Results depends on the location of parameter "a" in the plot command  
line. It turns out to be that the 1st plot is right, but the second  
plot (just the same equation but written differently) is wrong.

Is it a known problem?

Regards,

Raf

### ### 1st Plot ### ###

set terminal postscript landscape enhanced "Times-Roman" 22; set  
output "GoodPlot.ps"
set key top left; set grid
set xrange [0.22:2.5]
dH=8 ; dT=6
plot f(x) = 0.5*dT*x*60*sqrt(x**2+(pi*a*(dH-dT)/60)**2)/a, \
         a =  30, f(x) lw 4 title "N_O = &{0}30",\
         a =  50, f(x) lw 4 title "N_O = &{0}50",\
         a = 100, f(x) lw 4 title "N_O = 100",\
         a = 200, f(x) lw 4 title "N_O = 200",\
         a = 300, f(x) lw 4 title "N_O = 300"

### ### 2nd Plot ### ###
set terminal postscript landscape enhanced "Times-Roman" 22; set  
output "WrongPlot.ps"
set key top left; set grid
set xrange [0.22:2.5]
dH=8 ; dT=6
plot f(x) = 0.5*dT*x*(60/a)*sqrt(x**2+(pi*(a/60)*(dH-dT))**2), \
         a =  30, f(x) lw 4 title "N_O = &{0}30 rpm",\
         a =  50, f(x) lw 4 title "N_O = &{0}50 rpm",\
         a = 100, f(x) lw 4 title "N_O = 100 rpm",\
         a = 200, f(x) lw 4 title "N_O = 200 rpm",\
         a = 300, f(x) lw 4 title "N_O = 300 rpm"