Exemplary embodiments provide methods, mediums, and systems for comparing a sample of interest to a library of known compounds to quickly determine how similar the sample is to the compounds in the library. Peaks of interest in the sample data are compared to corresponding peaks in the library compound data. These peaks may be represented as vectors, and an angle between the sample vector and the library vector may be used as a similarity metric. In some embodiments, a cosine similarity may be calculated for the vectors. If the similarity score for a given library compound/sample pair exceed a threshold, then the system determines that the library compound and the sample are similar and takes appropriate action. Various parameters associated with the comparison can be adjusted in order to improve the quality of the results and/or the efficiency of the process.