Hi,
the human micro-array data provides the z-score and according to
http://help.brain-map.org/display/humanbrain/API
“* a vector of z-score values in the same order as the “samples” array. Note: z-score is computed independently for each probe over all donors and samples.”
i re-calculated the z-score for each probe with this formula, but i am unable to obtain the same z-score-values as provided in the dataset:
(expression_level - expression_level.mean())/expression_level.std()
I obtained data using this rma-query:
“http://api.brain-map.org/api/v2/data/query.json?criteria=”
f"model::Probe,rma::criteria,gene[acronym$il{self.geneAcronym}],rma::options[num_rows$eqall],"
“pipe::list[probes$eq’id’],”
“service::human_microarray_expression[probes$eq$probes]”
You can get the expression-levels and z-scores for the second probe here:
https://drive.google.com/open?id=1e3bBJGT-gX7eElDbKe1blXDpV-D07Cxs
how do I correctly calculate the z-score on behalf of this data?
some background: we are trying to compare z-scores for human-microarray data with mouse ish-data , which is unfortunatelly not providing z-scores. alternatively: how can we obtain z-scores for ISH using the api/sdk that are consistent with the z-scores from microarray-data?
thanks and regards
Christoph