R plot_ly row or dataframe in PowerBI custom visuals - r

Question

I am following: http://radacad.com/create-custom-visual-with-r-and-json-part3
Here it is mentioned that with below R code, we can plot the chart:
Values<-data.frame(X,Y,Legend,Row,Column)
g=ggplot(Values, aes(x=X, y=Y,colour = Legend))
I am using similar implementations.
Below code renders blank chart with only axis:
Values <- data.frame(mpg_test, cyl_test)
p <- plot_ly(Values,
x = ~mpg_test,
y = ~cyl_test,
name = "SF Zoo",
type = "bar"
)
Empty chart
Below code also renders empty chart:
Values <- data.frame(mpg_test, cyl_test)
p <- plot_ly(Values,
x = mpg_test,
y = cyl_test,
name = "SF Zoo",
type = "bar"
)
Below code renders correct chart:
Values <- data.frame(mpg_test, cyl_test)
p <- plot_ly(Values,
x = ~mpg_test[1:nrow(Values), ],
y = ~cyl_test[1:nrow(Values), ],
name = "SF Zoo",
type = "bar"
)
Correct chart:
My doubt is, as per the tutorial I must get columns in mpg_test and cyl_test, then why I am getting something like dataframe in here.
Does, plotly handles things differently with the usage of ~ ?
Please help. Also, is there any way I can use the mpg_test and cyl_test without nrow(Values) inside plot_ly
script.r
source('./r_files/flatten_HTML.r')
############### Library Declarations ###############
libraryRequireInstall("ggplot2");
libraryRequireInstall("plotly")
####################################################
################### Actual code ####################
Values <- data.frame(mpt_test, cyl_test)
p <- plot_ly(Values,
x = ~mpt_test[1:nrow(Values), ],
y = ~cyl_test[1:nrow(Values), ],
name = "SF Zoo",
type = "bar"
)
####################################################
############# Create and save widget ###############
#p = ggplotly(p);
internalSaveWidget(p, 'out.html');
####################################################
capabilities.json
{
"dataRoles": [
{
"displayName": "Mileage Per Gallon",
"kind": "GroupingOrMeasure",
"name": "mpg_test"
},
{
"displayName": "Cylinder Size",
"kind": "GroupingOrMeasure",
"name": "cyl_test"
}
],
"dataViewMappings": [
{ "conditions": [
{
"mpg_test": {
"max": 1
},
"cyl_test": {
"max": 1
}
}
],
"scriptResult": {
"dataInput": {
"table": {
"rows": {
"select": [
{
"for": {
"in": "mpg_test"
}
},
{
"for": {
"in": "cyl_test"
}
}
],
"dataReductionAlgorithm": {
"top": {}
}
}
}
},
"script": {
"scriptProviderDefault": "R",
"scriptOutputType": "html",
"source": {
"objectName": "rcv_script",
"propertyName": "source"
},
"provider": {
"objectName": "rcv_script",
"propertyName": "provider"
}
}
}
}
],
"objects": {
"rcv_script": {
"properties": {
"provider": {
"type": {
"text": true
}
},
"source": {
"type": {
"scripting": {
"source": true
}
}
}
}
}
},
"suppressDefaultTitle": true
}