NA_Real Values in For Loop

[akh1007]

Hi everyone, I am trying to read some values into R and then calculate an SST values, but my initial SST loop will not run properly. I keep getting "NA_Real" values. My code is pretty long so I abbreviated it below,

rm(list=ls())

val <- 0
s <- 0

meanval = 0
SST = 0

data<-read.csv("Qpeak Values.csv", header=TRUE)

#read in every value in table
val[1] = data[2,2]
val[2] = data[3,2]
val[3] = data[4,2]
val[4] = data[5,2]
val[5] = data[6,2]
val[6] = data[7,2]
#supposed to be 27 values but I edited them out

#loop to calc all SST's (I have 27 values so my code is looping 1:27)
for(i in 1:6){
SST = SST + ((val[i]-mean(val))^2)
}

After this loop I then calculate all my other SST values that not need to be looping. Since this loop above is getting "NA_real" values, my SST values after the loop are not being calculated.

Could I please have some advice on how to fix my loop?

[williaml]

Do you need to use a loop? Can you provide a reproducible example?

FAQ: What's a reproducible example (`reprex`) and how do I create one?

Why reprex? Getting unstuck is hard. Your first step here is usually to create a reprex, or reproducible example. The goal of a reprex is to package your code, and information about your problem so that others can run it and feel your pain. Then, hopefully, folks can more easily provide a solution. What's in a Reproducible Example? Parts of a reproducible example: background information - Describe what you are trying to do. What have you already done? complete set up - include any library() calls and data to reproduce your issue. data for a reprex: Here's a discussion on setting up data for a reprex make it run - include the minimal code required to reproduce your error on the data…

[woodward]

You just need to check for NA values.

for(i in 1:6){
  if (!is.na(val[i])){
    SST <- SST + (val[i]-mean(val, na.rm = TRUE))^2
  }
}

By the way, in R you would not usually use a loop for this, it's inefficient. This is better:

SST <- sum((val-mean(val, na.rm = TRUE))^2, na.rm = TRUE)

or

val <- val[!is.na(val)]
SST <- sum((val-mean(val))^2)