User function in "using" expression

[l***@aol.com]

I'm trying to use gnuplot to solve a specific version of the problem

3d plot z(x,y) with x,ys subject to the constraint f(x,y)=0

The following works (the files are 0 contours captured by set table)

array n[6]
file(i) = sprintf("coma%d.gpt",i)
splot for [i=1:|n|] file(i) using 1:2:(0):(0):(0):(1) with vectors

but if I also do:

phi(x,y) = (1+x)/(1+sqrt(1+(x*x-1)*y))
spher(n,x,y) = (f=phi(x,y),n2=n*n,((f-n)^2*(f-n2)*(1-y*f)-f^3)/(n2*(n-1)^3))
splot for [i=1:|n|] file(i) using 1:2:(0):(0):(0):(spher(n[i],$1,$2)) with vectors

I get the following message:

non-integer passed to boolean operator

What am I missing? I can provide the full file if needed.

Al

[Karl Ratzsch]

Post by l***@aol.com
I'm trying to use gnuplot to solve a specific version of the problem
3d plot z(x,y) with x,ys subject to the constraint f(x,y)=0
The following works (the files are 0 contours captured by set table)
array n[6]
file(i) = sprintf("coma%d.gpt",i)
splot for [i=1:|n|] file(i) using 1:2:(0):(0):(0):(1) with vectors
phi(x,y) = (1+x)/(1+sqrt(1+(x*x-1)*y))
spher(n,x,y) = (f=phi(x,y),n2=n*n,((f-n)^2*(f-n2)*(1-y*f)-f^3)/(n2*(n-1)^3))
splot for [i=1:|n|] file(i) using 1:2:(0):(0):(0):(spher(n[i],$1,$2)) with vectors
non-integer passed to boolean operator

the exponential operator in gnuplot is ** , not ^

I didnt know about this one

| |A| cardinality of array A

thanks. ;)

Karl

[l***@aol.com]

Karl,

Duh! I knew that but copied the expression from another software and forgot to make the changes. Advantage of having a second set of eyes.

Thanks,
Al

[Karl Ratzsch]

Post by l***@aol.com
I'm trying to use gnuplot to solve a specific version of the problem
3d plot z(x,y) with x,ys subject to the constraint f(x,y)=0
The following works (the files are 0 contours captured by set table)
array n[6]
file(i) = sprintf("coma%d.gpt",i)
splot for [i=1:|n|] file(i) using 1:2:(0):(0):(0):(1) with vectors
phi(x,y) = (1+x)/(1+sqrt(1+(x*x-1)*y))
spher(n,x,y) = (f=phi(x,y),n2=n*n,((f-n)^2*(f-n2)*(1-y*f)-f^3)/(n2*(n-1)^3))
splot for [i=1:|n|] file(i) using 1:2:(0):(0):(0):(spher(n[i],$1,$2)) with vectors
non-integer passed to boolean operator
What am I missing? I can provide the full file if needed.
Al

gnuplot uses