MATLAB: Matlab 2014b error while running the mapreduce

Question

Hi,

I have recently switched to Matlab 2014b. I am trying to run the mapreduce example (given in the 2014b documentation) to find Maximum Value of a single variable in a data set using mapreduce on local cluster. I am getting the following error while executing the script.

ds = datastore('airlinesmall.csv', 'TreatAsMissing', 'NA');

ds.SelectedVariableNames = 'ArrDelay';

type maxArrivalDelayMapper.m

type maxArrivalDelayReducer.m

maxDelay = mapreduce(ds, @maxArrivalDelayMapper, @maxArrivalDelayReducer);

Starting parallel pool (parpool) using the 'local' profile … connected to 4 workers.

Parallel mapreduce execution on the local cluster:

******************************

• MAPREDUCE PROGRESS *

******************************

Map 0% Reduce 0%

Analyzing and transferring files to the workers …done.

Error using mapreduce (line 100)

Internal error in the mapreduce framework detected during execution of mapreduce.

Caused by:

    An error occurred interpreting function call.

I have been getting the same error while trying to run the other examples from the documentation. What am I missing here?

Thanks in advance, Rajesh

Answer 1

Guess I got the answer. All I needed to do was to define execution environment for mapreduce. So I simply ran

mapreducer(0)

This sets the global execution environment for mapreduce to be the local MATLAB session. And all done.