Need help solving: error in heatmap(cell_cycle_m) : 'x' must be a numeric matrix

Question

[michelafrancesconi8]

I try to do a heatmap but I don't understand the error because I convert my dataframe in a matrix and also because all the data inside the dataframe are numeric, can someone help me?

cell_cycle_m <- as.matrix(cell_cycle_m)

heatmap(cell_cycle_m) Error in heatmap(cell_cycle_m) : 'x' must be a numeric matrix

[ATpoint]

What is the heatmap supposed to show? Columns 1-2 are not numeric but character.

[michelafrancesconi8]

Ok thank you