# Issue

*This Content is from Stack Overflow. Question asked by P i *

My dataframe has N rows.

I have M centroids. Each centroid is the same shape as a dataframe-row.

I need to create a Nrows by Mcols matrix, where the m-th column is created by applying the m-th centroid to the dataframe.

My solution involves pre-creating the output matrix and filling it one column at a time as we manually iterate over centroids.

It feels clumsy. But I can’t see clearly how to do it ‘properly’.

```
def getDistanceMatrix(df, centroids):
distanceMatrix = np.zeros((len(df), len(centroids)))
distFunc = lambda centroid, row: sum(centroid != row)
iCentroid = 0
for _, centroid in centroids.iterrows():
distanceMatrix[:, iCentroid] = df.apply(
lambda row: distFunc(centroid, row),
axis=1
)
iCentroid += 1
return distanceMatrix
distanceMatrix = getDistanceMatrix(df, centroids)
```

It feels like some kind of outer-product-with-a-custom-function.

What’s a good way to write this?

# Solution

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