Error: LoadError: MethodError: getindex has no method matching getindex(:DataFrames.DataFrame, :: ASCIIString)

[DaronAyer]

Below after the line of ****'s is the I am trying to run. It is a tutorial from the Kaggle website dealing with character recognition. I am getting an error when I try to run this:

xTrain = read_data("train", labelsInfoTrain, imageSize, path)

portion of the code. The error seems to be the result of a conflict between Images and DataFrames, the error occurs when the above portion of the code gets to this part:

for (index, idImage) in enumerate(labelsInfoTrain["ID"])

and then I get the error:

Error: LoadError: MethodError: `getindex` has no method matching getindex(::DataFrames.DataFrame, :: ASCIIString)

Look forward to hearing about this

---

#Install required packages
Pkg.add("Images")
Pkg.add("DataFrames")
using Images
using DataFrames


#typeData could be either "train" or "test.
#labelsInfo should contain the IDs of each image to be read
#The images in the trainResized and testResized data files
#are 20x20 pixels, so imageSize is set to 400.
#path should be set to the location of the data files.

function read_data(typeData, labelsInfo, imageSize, path)

#Intialize x matrix
 x = zeros(size(labelsInfo, 1), imageSize)

 for (index, idImage) in enumerate(labelsInfoTrain["ID"])
  #Read image file
  nameFile = "$(path)/$(typeData)Resized/$(idImage).Bmp"
  img = imread(nameFile)
  #Convert img to float values
  temp = float32sc(img)
  #Convert color images to gray images
  #by taking the average of the color scales.
  if ndims(temp) == 3
   temp = mean(temp.data, 1)
  end
  #Transform image matrix to a vector and store
  #it in data matrix
  x[index, :] = reshape(temp, 1, imageSize)
 end
 return x
end
imageSize = 400 # 20 x 20 pixels

#Set location of data files , folders
path = "C:\\Users\\Aaron\\Downloads\\Math512Project"

#Read i
labelsInfoTest = readtable("$(path)/sampleSubmissionJulia.csv")

#Read test matrixnformation about training data , IDs.
labelsInfoTrain = readtable("$(path)/trainLabels.csv")

#Read training matrix
xTrain = read_data("train", labelsInfoTrain, imageSize, path)

#Read information about test data ( IDs ).
labelsInfoTest = readtable("$(path)/sampleSubmissionJulia.csv")

#Read test matrix
xTest = read_data("test", labelsInfoTest, imageSize, path)

#Get only first character of string (convert from string to character).
#Apply the function to each element of the column "Class"
yTrain = map(x -> x[1], labelsInfoTrain["Class"])

#Convert from character to integer
yTrain = int(yTrain)

Pkg.add("DecisionTree")
Pkg.build("DecisionTree")
using DecisionTree

#Train random forest with
#20 for number of features chosen at each random split,
#50 for number of trees,
#and 1.0 for ratio of subsampling.
model = build_forest(yTrain, xTrain, 20, 50, 1.0)

#Get predictions for test data
predTest = apply_forest(model, xTest)

#Convert integer predictions to character
labelsInfoTest["Class"] = char(predTest)

#Save predictions
writetable("$(path)/juliaSubmission.csv", labelsInfoTest, separator=',', header=true)

#Run 4 fold cross validation
accuracy = nfoldCV_forest(yTrain, xTrain, 20, 50, 4, 1.0);
println ("4 fold accuracy: $(mean(accuracy))")

[yuyichao]

This is a user question about packages that should go to the julia-user mailing list.

I've never used the DataFrames package but a breif look at it suggests that you might want to index it with a symbol instead of a string i.e. lablesInfoTrain[:ID].

P.S. Please quote your code so that it's easier to tell them from your comments.

[tkelman]

ref https://groups.google.com/forum/?nomobile=true#!topic/julia-users/NISyks0j7gw

Try not to double post in different places. Mailing list should be first place to go with questions. If someone responds with a "yes that looks like a bug, please open an issue with a cross-reference link back to this thread" then it's okay, but that happens in a small subset of posts.

[DaronAyer]

Hi Tony,

Sorry for contacting you directly. I am new to this kind of thing. I
believe i posted my problem in the correct area, this is the Julia-users,
thread. Now do i wait until someone can help me ?

On Mon, Oct 26, 2015 at 9:46 PM, Tony Kelman [email protected]
wrote:

ref
https://groups.google.com/forum/?nomobile=true#!topic/julia-users/NISyks0j7gw

Try not to double post in different places. Mailing list should be first
place to go with questions. If someone responds with a "yes that looks like
a bug, please open an issue with a cross-reference link back to this
thread" then it's okay, but that happens in a small subset of posts.

—
Reply to this email directly or view it on GitHub
#13782 (comment).

Aaron Dyer
University of Delaware '15
Bachelors of Arts in Mathematics
Career Ambassador Program President

[johnmyleswhite]

Daron, you need to use a symbol instead of a string, so replace labelsInfoTrain["ID"] with labelsInfoTrain[:ID].

In the future, usage questions like this should really go to StackOverflow or the julia-users Google Group. If you're unfamiliar with either, you should start using StackOverflow for a few months. They're a very supportive community who have the resources to help get you on track. We unfortunately don't have enough people with free time on their hands to answer most usage questions.

[DaronAyer]

Hi John,
My team and I have tried your suggestion multiple times and doing so it causes another error in our code at this portion:

xTrain = read_data("train", labelsInfoTrain, imageSize, path)

The error reads:

imread not defined
in read_data at rf_julia_benchmark.jl:21

any suggestions

[johnmyleswhite]

Please post all questions to StackOverflow.