%%%Please try these commands. 1/0 ans = Inf exp(i*pi) ans = -1.0000 + 0.0000i j ans = 0 + 1.0000i 1i ans = 0 + 1.0000i 1j ans = 0 + 1.0000i 1i, 1j % safer usage ans = 0 + 1.0000i ans = 0 + 1.0000i Inf/Inf % not a number (undefined value) ans = NaN days_since_birth = floor(now) - datenum(1948,02,25) days_since_birth = 22412 now ans = 7.3396e+005 eps % machine precision on this computer ans = 2.2204e-016 who Your variables are: ans days_since_birth x whos Name Size Bytes Class Attributes ans 1x1 8 double days_since_birth 1x1 8 double x 1x1 8 double load usapolygon plot(uslon,uslat) who Your variables are: ans description uslat x days_since_birth source uslon load durer image(X) colormap(map) image(X) colormap(map) diary off