finding multivariate pdf of normally distributed data?

Assume my data is multivariate normally distributed. how i can plot the pdf of my first variable? say I have data matrix below with four variables

A =

     5    11    10     8

     9     7     6    12

     4    14    15     1

     4    14    15     1

     9     7     6    12
my mean is say
M=
     4    14    15     1
my covariance matrix is
Cov=
     16     2     3    13
      5    11    10     8
      9     7     6    12
      4    14    15     1

I used mvnpdf(A(:,1),M(:,1),cov(:,1)). any help would be appreciated.

[José-Luis]

Cov is not a covariance matrix.

Answer 1

[SK]

Do you want the histogram of the data. If so, use the hist() function.

If you want a theoretical normal marginal pdfs from the covariance and mean, use the diagonal terms from the covariance matrix as the variance for each variable. So for example, for the first variable:

x = 4-3*16 : 0.01 : 4+3*16;
y = pdf('normal', x, 4, 16);
plot(x(:), y(:));