if command with @(x,t) equation

I want to always display error but not when error only equal zero; so far, this is what I got, but it only works when error only equal zero. thks for your help

[madhan ravi]

upload the full code

[Adam]

Well, clearly your elseif statement has a couple of problems:

Firstly the first part of it is identical to the if statement so would never get hit anyway because your code would always land in the if statement.

Then, in the same vein, the thing you and it with is its exact inverse so that statement would always evaluate to false, just like if you had the statement:

if true & false

[madhan ravi]

in addition to that you can't compare a function handle ! unless it's evaluated

[May97]

so it is impossible to have an ''only if'' command in matlab??

[Stephen23]

It is also highly unlikely that the floating point operations exp and cos will every evaluate to give exactly zero for that formula. This is unlikely to be a useful approach to take with floating point calculations.

[Adam]

'Only if' is just an if statement, e.g.

if x == 0
   disp( 'x is 0'
end

[May97]

it does not, but since for 3b uexact is not given, i cannot calcute the error. I want to use the same function for both 3a and 3b

Answer 1

[Torsten]

https://stackoverflow.com/questions/18183648/matlab-check-if-function-handle-is-a-particular-function-or-function-type

[madhan ravi]

+1 Torsten you are absolut!