Making a histogram with data from excel

I have an Excel document with data points. I have entered in

D=[2437, 2437, ..., 2411];

then i attempt to make a histogram with hist(D,10) but it says

error
 variable D not known.

Didn't I just define D?

Answer 1

[madhan ravi]

[num,~,~]=xlsread('myexcelfile.xlsx')  %if it doesn't work upload excel file

D=num;

histogram(D,10)