How can I get rid of the error showing "Undefined function 'abs' for input arguments of type 'Interface​.00020846_​0000_0000_​C000_00000​0000046' "?

clc(); clear all; exl=actxserver('excel.application') exlwkbk=exl.Workbooks exlfile=exlwkbk.Open([docroot '\Delhi_CodaQ.xlsx']) exlsheet1=exlfile.Sheets.Item('07-09-2011_Ali') data=exlsheet1.Columns.End(2) numrows=data.rows dat_range=['B' num2str(numrows)]

My data is in the B column of excel file '07-09-2011_Ali' which I need to store in a MATLAB variable. The last line of my code is showing error saying Undefined function 'abs' for input arguments of type 'Interface.00020846_0000_0000_C000_000000000046' followed by the line Error in num2str (line 65) xmax = double(max(abs(widthCopy(:)))); How to solve this problem?