Hi Rohit,
Thank you. But unfortunately I still have the same error message. No, chkinputdatatype function is not shadowed. I ran " >> which -all chkinputdatatype" and the single output was C:\Program Files\MATLAB\R2014a\toolbox\signal\signal\private\chkinputdatatype.m % Private to signal. I ran at Matlab201b and the single output was C:\Program Files\MATLAB\R2014b\toolbox\signal\signal\private\chkinputdatatype.m % Private to signal. I do not rename the other files because I do not have them. After, I ran ">> restoredefaultpath", ">> rehash toolboxcache". But, I do have the same error message in both 2014a and 2014b.