Calculate the pearson correlation between two lists - r

I have many equally structured text files containing experimental data (641*976). At the beginning I define the correct "working directory" and order all the files in a list. Thereby I generate two different lists. Once the file.listx containing my sample data and once the file.listy containing reference data. Afterwards I rearrange the data in order to conduct the correlation analysis. Here the code shows how I generate the "x" list. The "y" list was generated exactly the same way with the reference data.
file.listx <- list.files(pattern="*.txt", full.names=T)
datalist = lapply(file.listx, FUN=read.table, header = F, sep = "\t", skip = 2)
cmbn = expand.grid(1:641, 1:977)
flen = length(datalist)
x=lapply(1:(nrow(cmbn)),function(t,lst,cmbn){
return(sapply(1:flen,function(i,t1,lst1,cmbn1){
return(lst1[[i]][cmbn1$Var1[t1],cmbn1$Var2[t1]])},t,lst,cmbn))}
,datalist,cmbn)
Now I want to calculate the pearson correlation between the two lists.
http://www.datasciencemadesimple.com/pearson-function-in-excel/
According to the pearson correlation formula corresponds my "x" to the sample and my "y" to the reference.
cor(x, y, method = "pearson")
Then the error message pops up that 'x' must be numeric. I do not know how I can solve this problem. When I use,
x = as.numeric(x)
it seems that the list structure gets lost. And the following approach does also not solve the problem.
x = as.matrix(x)
How can I convert my list into a numeric type without loosing the structure? I want to calculate the pearson correlation between the two lists.
Here is the code to generate two dummy lists. This way the error can be reproduced.
x = list(4:10, 10:16, 32:38, 100:106) # sample
y = list(10:16, 20:26, 40:46, 110:116) # reference
cor(x, y, method = "pearson")

Related

How to input matrix data into brms formula?

I am trying to input matrix data into the brm() function to run a signal regression. brm is from the brms package, which provides an interface to fit Bayesian models using Stan. Signal regression is when you model one covariate using another within the bigger model, and you use the by parameter like this: model <- brm(response ~ s(matrix1, by = matrix2) + ..., data = Data). The problem is, I cannot input my matrices using the 'data' parameter because it only allows one data.frame object to be inputted.
Here are my code and the errors I obtained from trying to get around that constraint...
First off, my reproducible code leading up to the model-building:
library(brms)
#100 rows, 4 columns. Each cell contains a number between 1 and 10
Data <- data.frame(runif(100,1,10),runif(100,1,10),runif(100,1,10),runif(100,1,10))
#Assign names to the columns
names(Data) <- c("d0_10","d0_100","d0_1000","d0_10000")
Data$Density <- as.matrix(Data)%*%c(-1,10,5,1)
#the coefficients we are modelling
d <- c(-1,10,5,1)
#Made a matrix with 4 columns with values 10, 100, 1000, 10000 which are evaluation points. Rows are repeats of the same column numbers
Bins <- 10^matrix(rep(1:4,times = dim(Data)[1]),ncol = 4,byrow =T)
Bins
As mentioned above, since 'data' only allows one data.frame object to be inputted, I've tried other ways of inputting my matrix data. These methods include:
1) making the matrix within the brm() function using as.matrix()
signalregression.brms <- brm(Density ~ s(Bins,by=as.matrix(Data[,c(c("d0_10","d0_100","d0_1000","d0_10000"))])),data = Data)
#Error in is(sexpr, "try-error") :
argument "sexpr" is missing, with no default
2) making the matrix outside the formula, storing it in a variable, then calling that variable inside the brm() function
Donuts <- as.matrix(Data[,c(c("d0_10","d0_100","d0_1000","d0_10000"))])
signalregression.brms <- brm(Density ~ s(Bins,by=Donuts),data = Data)
#Error: The following variables can neither be found in 'data' nor in 'data2':
'Bins', 'Donuts'
3) inputting a list containing the matrix using the 'data2' parameter
signalregression.brms <- brm(Density ~ s(Bins,by=donuts),data = Data,data2=list(Bins = 10^matrix(rep(1:4,times = dim(Data)[1]),ncol = 4,byrow =T),donuts=as.matrix(Data[,c(c("d0_10","d0_100","d0_1000","d0_10000"))])))
#Error in names(dat) <- object$term :
'names' attribute [1] must be the same length as the vector [0]
None of the above worked; each had their own errors and it was difficult troubleshooting them because I couldn't find answers or examples online that were of a similar nature in the context of brms.
I was able to use the above techniques just fine for gam(), in the mgcv package - you don't have to define a data.frame using 'data', you can call on variables defined outside of the gam() formula, and you can make matrices inside the gam() function itself. See below:
library(mgcv)
signalregression2 <- gam(Data$Density ~ s(Bins,by = as.matrix(Data[,c("d0_10","d0_100","d0_1000","d0_10000")]),k=3))
#Works!
It seems like brms is less flexible... :(
My question: does anyone have any suggestions on how to make my brm() function run?
Thank you very much!
My understanding of signal regression is limited enough that I'm not convinced this is correct, but I think it's at least a step in the right direction. The problem seems to be that brm() expects everything in its formula to be a column in data. So we can get the model to compile by ensuring all the things we want are present in data:
library(tidyverse)
signalregression.brms = brm(Density ~
s(cbind(d0_10_bin, d0_100_bin, d0_1000_bin, d0_10000_bin),
by = cbind(d0_10, d0_100, d0_1000, d0_10000),
k = 3),
data = Data %>%
mutate(d0_10_bin = 10,
d0_100_bin = 100,
d0_1000_bin = 1000,
d0_10000_bin = 10000))
Writing out each column by hand is a little annoying; I'm sure there are more general solutions.
For reference, here are my installed package versions:
map_chr(unname(unlist(pacman::p_depends(brms)[c("Depends", "Imports")])), ~ paste(., ": ", pacman::p_version(.), sep = ""))
[1] "Rcpp: 1.0.6" "methods: 4.0.3" "rstan: 2.21.2" "ggplot2: 3.3.3"
[5] "loo: 2.4.1" "Matrix: 1.2.18" "mgcv: 1.8.33" "rstantools: 2.1.1"
[9] "bayesplot: 1.8.0" "shinystan: 2.5.0" "projpred: 2.0.2" "bridgesampling: 1.1.2"
[13] "glue: 1.4.2" "future: 1.21.0" "matrixStats: 0.58.0" "nleqslv: 3.3.2"
[17] "nlme: 3.1.149" "coda: 0.19.4" "abind: 1.4.5" "stats: 4.0.3"
[21] "utils: 4.0.3" "parallel: 4.0.3" "grDevices: 4.0.3" "backports: 1.2.1"

How to load a csv file into R as a factor for use with glmnet and logistic regression

I have a csv file (single column, numeric values) called "y" that consists of zeros and ones where the rows with the value 1 indicate the target variable for logistic regression, and another file called "x" with the same number of rows and with columns of numeric predictor values. How do I load these so that I can then use cv.glmnet, i.e.
x <- read.csv('x',header=FALSE,sep=",")
y <- read.csv('y',header=FALSE )
is throwing an error
Error in y %*% rep(1, nc) :
requires numeric/complex matrix/vector arguments
when I call
cvfit = cv.glmnet(x, y, family = "binomial")
I know that "y" should be loaded as a "factor," but how do I do this? My online searches have found all sorts of approaches that have just confused me. What is the simple one-liner to just load this data ready for glmnet?
The cv.glmnet requires data to be provided in vector or matrix format. You can use the following code
xmat = as.matrix(x)
yvec = as.vector(y)
Then use
cvfit = cv.glmnet(xmat, yvec, family = "binomial")
If you can provide your data in dput() format, I can give a try.

error with rda test in vegan r package. Variable not being read correctly

I am trying to perform a simple RDA using the vegan package to test the effects of depth, basin and sector on genetic population structure using the following data frame.
datafile.
The "ALL" variable is the genetic population assignment (structure).
In case the link to my data doesn't work well, I'll paste a snippet of my data frame here.
I read in the data this way:
RDAmorph_Oct6 <- read.csv("RDAmorph_Oct6.csv")
My problems are two-fold:
1) I can't seem to get my genetic variable to read correctly. I have tried three things to fix this.
gen=rda(ALL ~ Depth + Basin + Sector, data=RDAmorph_Oct6, na.action="na.exclude")
Error in eval(specdata, environment(formula), enclos = globalenv()) :
object 'ALL' not found
In addition: There were 12 warnings (use warnings() to see them)
so, I tried things like:
> gen=rda("ALL ~ Depth + Basin + Sector", data=RDAmorph_Oct6, na.action="na.exclude")
Error in colMeans(x, na.rm = TRUE) : 'x' must be numeric
so I specified numeric
> RDAmorph_Oct6$ALL = as.numeric(RDAmorph_Oct6$ALL)
> gen=rda("ALL ~ Depth + Basin + Sector", data=RDAmorph_Oct6, na.action="na.exclude")
Error in colMeans(x, na.rm = TRUE) : 'x' must be numeric
I am really baffled. I've also tried specifying each variable with dataset$variable, but this doesn't work either.
The strange thing is, I can get an rda to work if I look the effects of the environmental variables on a different, composite, variable
MC = RDAmorph_Oct6[,5:6]
H_morph_var=rda(MC ~ Depth + Basin + Sector, data=RDAmorph_Oct6, na.action="na.exclude")
Note that I did try to just extract the ALL column for the genetic rda above. This didn't work either.
Regardless, this leads to my second problem.
When I try to plot the rda I get a super weird plot. Note the five dots in three places. I have no idea where these come from.
I will have to graph the genetic rda, and I figure I'll come up with the same issue, so I thought I'd ask now.
I've been though several tutorials and tried many iterations of each issue. What I have provided here is I think the best summary. If anyone can give me some clues, I would much appreciate it.
The documentation, ?rda, says that the left-hand side of the formula specifying your model needs to be a data matrix. You can't pass it the name of a variable in the data object as the left-hand side (or at least if this was ever anticipated, doing so exposes bugs in how we parse the formula which is what leads to further errors).
What you want is a data frame containing a variable ALL for the left-hand side of the formula.
This works:
library('vegan')
df <- read.csv('~/Downloads/RDAmorph_Oct6.csv')
ALL <- df[, 'ALL', drop = FALSE]
Notice the drop = FALSE, which stops R from dropping the empty dimension (i.e. converting the single column data frame to a vector.
Then your original call works:
ord <- rda(ALL ~ Basin + Depth + Sector, data = df, na.action = 'na.exclude')
The problem is that rda expects a separate df for the first part of the formula (ALL in your code), and does not use the one in the data = argument.
As mentioned above, you can create a new df with the variable needed for analysis, but here's a oneline solution that should also work:
gen <- rda(RDAmorph_Oct6$ALL ~ Depth + Basin + Sector, data = RDAmorph_Oct6, na.action = na.exclude)
This is partly similar to Gavin simpson's answer. There is also a problem with the categorical vectors in your data frame. You can either use library(data.table) and the rowid function to set the categorical variables to unique integers. Most preferably, not use them. I also wanted to set the ID vector as site names, but I am too lazy now.
library(data.table)
RDAmorph_Oct6 <- read.csv("C:/........../RDAmorph_Oct6.csv")
#remove NAs before. I like looking at my dataframes before I analyze them.
RDAmorph_Oct6 <- na.omit(RDAmorph_Oct6)
#I removed one duplicate
RDAmorph_Oct6 <- RDAmorph_Oct6[!duplicated(RDAmorph_Oct6$ID),]
#Create vector with only ALL
ALL <- RDAmorph_Oct6$ALL
#Create data frame with only numeric vectors and remove ALL
dfn <- RDAmorph_Oct6[,-c(1,4,11,12)]
#Select all categorical vectors.
dfc <- RDAmorph_Oct6[,c(1,11,12)]
#Give the categorical vectors unique integers doesn't do this for ID (Why?).
dfc2 <- as.data.frame(apply(dfc, 2, function(x) rowid(x)))
#Bind back with numeric data frame
dfnc <- cbind.data.frame(dfn, dfc2)
#Select only what you need
df <- dfnc[c("Depth", "Basin", "Sector")]
#The rest you know
rda.out <- rda(ALL ~ ., data=df, scale=T)
plot(rda.out, scaling = 2, xlim=c(-3,2), ylim=c(-1,1))
#Also plot correlations
plot(cbind.data.frame(ALL, df))
Sector and depth have the highest variation. Almost logical, since there are only three vectors used. The assignment of integers to the categorical vector has probably no meaning at all. The function assigns from top to bottom unique integers to the following unique character string. I am also not really sure which question you want to answer. Based on this you can organize the data frame.

Apply PCA for data stored in list

My image data is stored in a list. For every pixel (626257) of my image I have a vector containing all the values corresponding to the different wavelengths (44 wavelengths). Now I would like to carry out a principal component analysis (PCA). Unfortunately, I am not able to convert my listed data into the desired form. Here is the code to generate a dummy data set.
test = replicate(626257, rnorm(44, 3, 1),simplify = FALSE)
When I now try to carry out the PCA then the following error message pops up.
pca = prcomp(test, scale = F)
Error in colMeans(x, na.rm = TRUE) : 'x' must be numeric
How can I convert my list into a suitable datatype?
We could change the simplify = TRUE in replicate and it should work
test <- replicate(10, rnorm(44, 3, 1),simplify = FALSE)
pca = prcomp(test, scale = FALSE)

Kaggle Digit Recognizer Using SVM (e1071): Error in predict.svm(ret, xhold, decision.values = TRUE) : Model is empty

I am trying to solve the digit Recognizer competition in Kaggle and I run in to this error.
I loaded the training data and adjusted the values of it by dividing it with the maximum pixel value which is 255. After that, I am trying to build my model.
Here Goes my code,
Given_Training_data <- get(load("Given_Training_data.RData"))
Given_Testing_data <- get(load("Given_Testing_data.RData"))
Maximum_Pixel_value = max(Given_Training_data)
Tot_Col_Train_data = ncol(Given_Training_data)
training_data_adjusted <- Given_Training_data[, 2:ncol(Given_Training_data)]/Maximum_Pixel_value
testing_data_adjusted <- Given_Testing_data[, 2:ncol(Given_Testing_data)]/Maximum_Pixel_value
label_training_data <- Given_Training_data$label
final_training_data <- cbind(label_training_data, training_data_adjusted)
smp_size <- floor(0.75 * nrow(final_training_data))
set.seed(100)
training_ind <- sample(seq_len(nrow(final_training_data)), size = smp_size)
training_data1 <- final_training_data[training_ind, ]
train_no_label1 <- as.data.frame(training_data1[,-1])
train_label1 <-as.data.frame(training_data1[,1])
svm_model1 <- svm(train_label1,train_no_label1) #This line is throwing an error
Error : Error in predict.svm(ret, xhold, decision.values = TRUE) : Model is empty!
Please Kindly share your thoughts. I am not looking for an answer but rather some idea that guides me in the right direction as I am in a learning phase.
Thanks.
Update to the question :
trainlabel1 <- train_label1[sapply(train_label1, function(x) !is.factor(x) | length(unique(x))>1 )]
trainnolabel1 <- train_no_label1[sapply(train_no_label1, function(x) !is.factor(x) | length(unique(x))>1 )]
svm_model2 <- svm(trainlabel1,trainnolabel1,scale = F)
It didn't help either.
Read the manual (https://cran.r-project.org/web/packages/e1071/e1071.pdf):
svm(x, y = NULL, scale = TRUE, type = NULL, ...)
...
Arguments:
...
x a data matrix, a vector, or a sparse matrix (object of class
Matrix provided by the Matrix package, or of class matrix.csr
provided by the SparseM package,
or of class simple_triplet_matrix provided by the slam package).
y a response vector with one label for each row/component of x.
Can be either a factor (for classification tasks) or a numeric vector
(for regression).
Therefore, the mains problems are that your call to svm is switching the data matrix and the response vector, and that you are passing the response vector as integer, resulting in a regression model. Furthermore, you are also passing the response vector as a single-column data-frame, which is not exactly how you are supposed to do it. Hence, if you change the call to:
svm_model1 <- svm(train_no_label1, as.factor(train_label1[, 1]))
it will work as expected. Note that training will take some minutes to run.
You may also want to remove features that are constant (where the values in the respective column of the training data matrix are all identical) in the training data, since these will not influence the classification.
I don't think you need to scale it manually since svm itself will do it unlike most neural network package.
You can also use the formula version of svm instead of the matrix and vectors which is
svm(result~.,data = your_training_set)
in your case, I guess you want to make sure the result to be used as factor,because you want a label like 1,2,3 not 1.5467 which is a regression
I can debug it if you can share the data:Given_Training_data.RData

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