How to show the variable name instead of its value in a plot's text, when using "syms", "text" and "latex" functions

4 views (last 30 days)
Question: By using both syms, latex and text functions/tools (as in the example here below), how can I show the variable name instead of its value, in a plot's text ?
What I currently have: In this example, if I assign a value to the variable "a", i.e. "a = 0.01", the latex function will show its value, i.e. "0.01" (i.e. "1/100") and not its name, i.e. "a".
syms x
a = 0.01 ;
y = exp(-a*x); % equation to show inside the plot
figure
fplot(y, [0 500])
text(100,0.5, ['$y = ' latex(y) '$'], 'Interpreter','latex', 'FontSize',16)
My desired output: If possible, I would like to still use both syms, latex and text functions/tools (as in my example), and see/show the variable name "a" in the plot's text, instead of its value "0.01" (i.e. "1/100").

Accepted Answer

Dyuman Joshi
Dyuman Joshi on 26 Aug 2022
syms y(a,x)
y(a,x) = exp(-a*x); % equation to show inside the plot
figure
fplot(y(0.01,x), [0 500])
text(100,0.5, ['$y = ' latex(y) '$'], 'Interpreter','latex', 'FontSize',16)

More Answers (1)

Walter Roberson
Walter Roberson on 26 Aug 2022
You cannot do that, not without reconstructing the formula
syms x
a = 0.01 ;
y = exp(-a*x); % equation to show inside the plot
children(y)
ans = 1×1 cell array
{[-x/100]}
children(ans{1})
ans = 1×2 cell array
{[x]} {[-1/100]}
Notice that there is no "a" anywhere in the breakout of the expression.
  2 Comments
Sim
Sim on 28 Aug 2022
thanks @Walter Roberson! ....but..... what do you think about the @Dyuman Joshi solution ?
It looks like working for my needs.... I mean, in that wasy I do not need to write the equation more than once....

Sign in to comment.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by