# matchms.calculate_scores module¶

matchms.calculate_scores.calculate_scores(references: , queries: , similarity_function: BaseSimilarity, is_symmetric: bool = False) [source]

Calculate the similarity between all reference objects versus all query objects.

Example to calculate scores between 2 spectrums and iterate over the scores

```import numpy as np
from matchms import calculate_scores, Spectrum
from matchms.similarity import CosineGreedy

spectrum_1 = Spectrum(mz=np.array([100, 150, 200.]),
intensities=np.array([0.7, 0.2, 0.1]),
spectrum_2 = Spectrum(mz=np.array([100, 140, 190.]),
intensities=np.array([0.4, 0.2, 0.1]),
spectrums = [spectrum_1, spectrum_2]

scores = calculate_scores(spectrums, spectrums, CosineGreedy())

for (reference, query, score) in scores:
print(f"Cosine score between {reference.get('id')} and {query.get('id')}" +
f" is {score['score']:.2f} with {score['matches']} matched peaks")
```

Should output

```Cosine score between spectrum1 and spectrum1 is 1.00 with 3 matched peaks
Cosine score between spectrum1 and spectrum2 is 0.83 with 1 matched peaks
Cosine score between spectrum2 and spectrum1 is 0.83 with 1 matched peaks
Cosine score between spectrum2 and spectrum2 is 1.00 with 3 matched peaks
```
Parameters
• references – List of reference objects

• queries – List of query objects

• similarity_function – Function which accepts a reference + query object and returns a score or tuple of scores

• is_symmetric – Set to True when references and queries are identical (as for instance for an all-vs-all comparison). By using the fact that score[i,j] = score[j,i] the calculation will be about 2x faster. Default is False.

Return type

Scores