Call Web Service to Extract Images
This experiment shows how to plot using ggplot2, and how to call this in RRS mode and extract images from the output base-64 encoded strings
This experiment has an Execute R Script module that creates 4 plots using ggplot2 library. You can see the plots by visualizing the 2nd output port of the Execute R Script module.
After deploying a web service out of this predictive experiment, you can then use the following PowerShell scripts to call the RRS endpoint and save the images as 4 png files locally.
Import-Module AzureMLPS.dll
$url = '**RRS Endpoint URL**'
$key = '**API Key**'
$saveToDir = 'c:\temp\'
# This web service has no input
$input = '{}'
# output in JSON format
$output = Invoke-AmlWebServiceRRSEndpoint -ApiLocation $url -ApiKey $key -InputJsonText $input
# convert to JSON object
$x1 = ConvertFrom-Json -InputObject $output
# get the inner JSON string from "output1"
$x2 = $x1.Results.output1.value.Values[0][0]
# convert to JSON object
$x3 = ConvertFrom-Json -InputObject $x2
# get the actual outputs: 0 is StdOut, 1 is StdErr, and 2 is Graphics Device
$x4 = $x3.sections[2].values
# save all plots to "c:\temp\n.png" where n = 1 to 4.
for ($i = 0; $i -lt $x4.Length; $i++) {
[io.file]::WriteAllBytes($saveToDir + $i.ToString() + '.png', [System.Convert]::FromBase64String($x4[$i].data))
}
To get the Azure ML Studio PowerShell Module, visit [http://aka.ms/amlps](http://aka.ms/amlps). You can also do this in C#/Python/R etc.
