CODEWITHSUNDEEP
razure-machine-learning-service
user330959
user330959

Reputation: 67

Azure ML and r scripts

I have dataframe with columns 

date    open    high    low     close   adjclose    volume

I want to add one more column named "result"(1 if close > open, 0 if close < open)

I do

# Map 1-based optional input ports to variables
data <- maml.mapInputPort(1) # class: data.frame



# calculate pass/fail
data$result <- as.factor(sapply(data$close,function(res) 
    if (res - data$open >= 0) '1' else '0'))

# Select data.frame to be sent to the output Dataset port
maml.mapOutputPort("data");

But I have only 1 in result. Where is the problem?

Upvotes: 1

Views: 113

Answers (1)

akrun
akrun

Reputation: 887048

The if/else can return only a single TRUE/FALSE and is not vectorized for length > 1. It may be suitable to use ifelse (but that is also not required and would be less efficient compared to direct coersion of logical vector to binary (as.integer). In the OP's code, the 'close' column elements are looped (sapply) and subtracted from the whole 'open' column. The intention might be to do elementwise subtraction. In that case, - between the columns is much cleaner and efficient (as these operations are vectorized)

data$result <- with(data, factor(as.integer((close - open) >= 0)))

In the above, we get the difference between the columns ('close', 'open'), check if it is greater than or equal to 0 (returns logical vector), convert it to binary (as.integer - TRUE -> 1, FALSE -> 0) and then change it to factor type (if needed)

Upvotes: 1

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