fplot keeps returning horizontal line

I am trying to evaluate the constituents of a source of Californium 252 after a certain number of days. I have defined an expression in terms of other variables that I want to plot. But 'fplot' seems to only return a horizontal line at Y=0. There is no error message when I run the script. Any help is greatly appreciated.

Answer 1

[Karan Gill]

You are plotting a constant Atom_Cf_P with value 1.8235e-78. A horizontal line is the expected output. What were you expecting?

[David M]

I was attempting to plot Atom_Cf_P as a function of T, time. I figured out i needed to use 'syms T' to define a variable for plotting. Thank you for your response. David

[madhan ravi]

whenever you plot a function declare it using sym and then use fplot otherwise Matlab will give a horizontal line at y=0.