Contouring irregularly spaced points

I have data at 132 irregularly spaced lat,lon locations that I want to create a contour map of using contourf

So, I have three vectors.

One vector is a 132 X 1 vector of the latitudes for these 132 locations (the y dimension) One vector is a 132 X 1 vector of the longitudes for these 132 locations (the x dimension) One vector is a 132 X 1 vector of the data value at these 132 locations (the Z dimension)

I've used contourf to make plots (maps) of regularly spaced data before but not irregularly spaced data.

The documentation for contourf states that z dimension should be of size X * Y and this is what's hanging me up. How do I take the vector Z and turn it into (a 132 x 132?) matrix before calling contourf?