gnuplot unable to plot a function

Question

I have the following gnuplot script which does not yield an output

set encoding utf8
set termoption enhanced

y(x) = 20 * log10(1/((1/694) * x))

set log x
set xrange [1:10]
set xlabel "{/Symbol w} 1/s"
set yrange [-150:150]
set ylabel "G^* dB"

plot y(x)

However, if I replace the y(x) function with something simpler, eg. y(x) = 20 * log10(1 / x) the script works as expected.

What is wrong with the function and why gnuplot is not able to plot it?

user8153 · Accepted Answer · 2017-10-05 23:35:11Z

4

In integer arithmetic (1/694) is equal to zero, so the argument of the logarithm is 1/(0*x), which is not numerical. To make sure you are using floating point arithmetic try

y(x) = 20 * log10(1./((1./694.) * x))

edited Oct 5, 2017 at 23:35

answered Oct 5, 2017 at 22:43

user8153

4,1251 gold badge11 silver badges18 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

gnuplot unable to plot a function

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest