How to do it...

The following code block plots a correlation matrix with a Blues colormap:

1. Read the winequality data from the Excel file:

wine_quality = pd.read_csv('winequality.csv', delimiter=';')
corr = wine_quality.corr()

2. Define the figure and its size:

plt.figure(figsize=(12,8))

3. Plot the correlation map, the associated x and y ticks, and the colorbar:

plt.imshow(corr, cmap='Blues')
plt.colorbar()
plt.xticks(range(len(corr)),corr.columns, rotation=45)
plt.yticks(range(len(corr)),corr.columns)

4. Display the figure on the screen:

plt.show()