How to read array of data series in json into Igor waves?

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I want to read data from a json file into Igor waves. The example file (s. below) contain a series with time stamps and 3 data series. I want to end the time stamps and the 3 data series each in an Igor wave. Optimally I could get the names for the waves from the json file ("unix times", "data 1", "data 2", "data 3").  

I can manage to parse the json file and to extract the series of time stamps.

Function dada()

	Variable jsonId
	
	JSONXOP_Parse(FetchURL("file:///Users/eckart/Desktop/response_shortened.txt"))
	jsonId = V_value
	
	JSONXOP_Dump jsonId
	print S_Value

	JSONXOP_GetArraySize jsonId, "/unix_seconds"
	print "Array size of unix_seconds :", V_value
	
	JSONXOP_GetArraySize jsonId, "/production_types"
	print "Array size of production_types:", V_value

	JSONXOP_GetValue/WAVE=tStamps jsonId, "/unix_seconds"
	
	JSONXOP_Release jsonId

end

But I am lost when it comes to extracting the 3 data series. I suspect I have to loop over the array in production_types, but cannot figure out the syntax.

 

Can someone please help?

 Example json (6.28 KB)

it is really not that difficult

Function dada()

	Variable k, jsonId, nProdTypes
	String str
	
	JSONXOP_Parse(FetchURL("file:///Users/eckart/Desktop/response_shortened.txt"))
	jsonId = V_value
	
	JSONXOP_Dump jsonId
	print S_Value

	JSONXOP_GetArraySize jsonId, "/unix_seconds"
	print "Array size of unix_seconds :", V_value
	
	JSONXOP_GetValue/WAVE=tStamps jsonId, "/unix_seconds"
	
	JSONXOP_GetArraySize jsonId, "/production_types"
	nProdTypes = V_value
	print "Array size of production_types:", nProdTypes
	
	k = 0	
	do
		sprintf str, "/production_types/%d/name", k
		JSONXOP_GetValue/T jsonId, str
		sprintf str, "/production_types/%d/data", k
		JSONXOP_GetValue/WAVE=$S_value jsonId, str
	
		k += 1
	while (k < nProdTypes)

	JSONXOP_Release jsonId

end

I hope someone will profit from me asking and answering.

March 25, 2024 at 12:24 pm - Permalink

Yes that looks correct. I personally prefer the JSON wrapper functions instead of the operations but that is more a taste thing. Depending on the size of the json file one could move the code in the do/while loop into a function and call that via wave indexing, Multithread does unfortunately not help as the JSON XOP does not allow concurrent read access.

March 25, 2024 at 01:02 pm - Permalink