How to read array of data series in json into Igor waves?
Eckart.Hasselbrink
Mon, 03/25/2024 - 10:25 am
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
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?
it is really not that difficult
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