Define variables before using them , Pass the right parameters to the ODE equation. https://nl.mathworks.com/matlabcentral/answers/504977-unrecognized-function-or-variable-x#comment_796153 Cancel Copy to Clipboard I am not very sure how to do that. That function has the property … https://de.mathworks.com/matlabcentral/answers/504977-unrecognized-function-or-variable-x#comment_796153 Cancel Copy to Clipboard I am not very sure how to do that. If the file exists, the path has somehow been removed.Restart Matlab and see if the problem goes away. Then with the character vector in hand, use str2double. Unrecognized function or variable . This is the result that I came up with: This person has a 5% chance to infect their neighbor. If it doesn't go away, check your startup.m file (if that file exists) to determine if you're removing important paths. If the user entered 1.23 at the input prompt, then '1.23' character vector would be returned, not the number 1.23. Learn more about function Sign in to answer this question. Unless you have explicitly created one axes don't have a createFcn set by default, so I assume you must have asked it to create one at some point then deleted it. You could also try running restoredefaultpath. This person has a 5% chance to infect their neighbor. Learn more about image processing Image Processing Toolbox Learn more about image processing Image Processing Toolbox Skip to content That's how you deal with it - make sure it exists as a variable that you expect regexp to act on in the workspace you are calling the function. Unrecognized function or variable . Sign in to comment. You could also try running restoredefaultpath. Learn more about function Use an anonymous function @(t,x) eqx3(t,x,eta, omega) to package the ODE parameters with the function, Use plot3 for 3D plotting of the phase portrait. Learn more about machine learning, carsmall, gplotmatrix Learn more about machine learning, carsmall, gplotmatrix Skip to content Learn more about unrecognized function or variable, error, minfunc Learn more about unrecognized function or variable, error, minfunc Skip to content If it doesn't go away, check your startup.m file (if that file exists) to determine if you're removing important paths. If the file exists, the path has somehow been removed.Restart Matlab and see if the problem goes away. I'm taking a Matlab class and have this homework assignment that requires me to select a random person in a town of 1000 to be infected with a virus. I'm taking a Matlab class and have this homework assignment that requires me to select a random person in a town of 1000 to be infected with a virus.