Vectorizing a for-loop for cross-validation in R
0
I'm trying to speed up a script that otherwise takes days to handle larger data sets. So, is there a way to completely vectorize the following script:
# k-fold cross validation
df <- trees # a data frame 'trees' from R.
df <- df[sample(nrow(df)), ] # randomly shuffles the data.
k <- 10 # Number of folds. Note k=nrow(df) in the leave-one-out cross validation.
folds <- cut(seq(from=1, to=nrow(df)), breaks=k, labels=FALSE) # creates unique numbers for k equally size folds.
df$ID <- folds # adds fold IDs.
df[paste("pred", 1:10, sep="")] <- NA # adds multiple columns "pred1"..."pred10" to speed up the following loop.
library(mgcv)
for(i in 1:k) {
# looping for different models:
m1 <- gam(Volume ~ s(Height), data=df, subset=(ID != i))
m2 <- gam(Volume ~ s(Girth), data=df, subset=(ID != i))
m3 <- gam(Volume ~ s(Girth) + s(Height), data=df, subset=(ID != i))
# looping for predictions:
df[df$ID==i, "pred1"] <- predict(m1, df[df$ID==i, ], type="response")
df[df$ID==i, "pred2"] <- predict(m2, df[df$ID==i, ], type="response")
df[df$ID==i, "pred3"] <- predict(m3, df[df$ID==i, ], type="response")
}
# calculating residuals:
df$res1 <- with(df, Volume - pred1)
df$res2 <- with(df, Volume - pred2)
df$res3 <- with(df, Volume - pred3)
Model <- paste("m", 1:10, sep="") # creates a vector of model names.
# creating a vector of mean-square errors (MSE):
MSE <- with(df, c(
sum(res1^2) / nrow(df),
sum(res2^2) / nrow(df),
sum(res3^2) / nrow(df)
))
model.mse <- data.frame(Model, MSE, R2) # creates a data frame of model names, mean-square errors and coefficients of determination.
model.mse <- model.mse[order(model.mse$MSE), ] # rearranges the previous data frame in order of increasing mean-square errors.
I'd appreciate any help. This code takes several days if run on 30,000 different GAM models and 3 predictors. Thanks
r
edited Jan 18 at 19:18
dww
14.8k22655
asked Jan 18 at 19:08
LexoLexo
1
add a comment |
0
I'm trying to speed up a script that otherwise takes days to handle larger data sets. So, is there a way to completely vectorize the following script:
# k-fold cross validation
df <- trees # a data frame 'trees' from R.
df <- df[sample(nrow(df)), ] # randomly shuffles the data.
k <- 10 # Number of folds. Note k=nrow(df) in the leave-one-out cross validation.
folds <- cut(seq(from=1, to=nrow(df)), breaks=k, labels=FALSE) # creates unique numbers for k equally size folds.
df$ID <- folds # adds fold IDs.
df[paste("pred", 1:10, sep="")] <- NA # adds multiple columns "pred1"..."pred10" to speed up the following loop.
library(mgcv)
for(i in 1:k) {
# looping for different models:
m1 <- gam(Volume ~ s(Height), data=df, subset=(ID != i))
m2 <- gam(Volume ~ s(Girth), data=df, subset=(ID != i))
m3 <- gam(Volume ~ s(Girth) + s(Height), data=df, subset=(ID != i))
# looping for predictions:
df[df$ID==i, "pred1"] <- predict(m1, df[df$ID==i, ], type="response")
df[df$ID==i, "pred2"] <- predict(m2, df[df$ID==i, ], type="response")
df[df$ID==i, "pred3"] <- predict(m3, df[df$ID==i, ], type="response")
}
# calculating residuals:
df$res1 <- with(df, Volume - pred1)
df$res2 <- with(df, Volume - pred2)
df$res3 <- with(df, Volume - pred3)
Model <- paste("m", 1:10, sep="") # creates a vector of model names.
# creating a vector of mean-square errors (MSE):
MSE <- with(df, c(
sum(res1^2) / nrow(df),
sum(res2^2) / nrow(df),
sum(res3^2) / nrow(df)
))
model.mse <- data.frame(Model, MSE, R2) # creates a data frame of model names, mean-square errors and coefficients of determination.
model.mse <- model.mse[order(model.mse$MSE), ] # rearranges the previous data frame in order of increasing mean-square errors.
I'd appreciate any help. This code takes several days if run on 30,000 different GAM models and 3 predictors. Thanks
r
edited Jan 18 at 19:18
dww
14.8k22655
asked Jan 18 at 19:08
LexoLexo
1
1
How long does each GAM model take? Not convinced the for loop is your problem.
– dww
Jan 18 at 19:22
Yes, profile your code and you'll see the time is spent fitting the models. Your best option is parallelization.
– Roland
Jan 18 at 23:15
Thanks! Could you please help with re-writing the script into sapply() or foreach()/doParallel format?
– Lexo
Jan 21 at 11:11
add a comment |
0
0
0
I'm trying to speed up a script that otherwise takes days to handle larger data sets. So, is there a way to completely vectorize the following script:
# k-fold cross validation
df <- trees # a data frame 'trees' from R.
df <- df[sample(nrow(df)), ] # randomly shuffles the data.
k <- 10 # Number of folds. Note k=nrow(df) in the leave-one-out cross validation.
folds <- cut(seq(from=1, to=nrow(df)), breaks=k, labels=FALSE) # creates unique numbers for k equally size folds.
df$ID <- folds # adds fold IDs.
df[paste("pred", 1:10, sep="")] <- NA # adds multiple columns "pred1"..."pred10" to speed up the following loop.
library(mgcv)
for(i in 1:k) {
# looping for different models:
m1 <- gam(Volume ~ s(Height), data=df, subset=(ID != i))
m2 <- gam(Volume ~ s(Girth), data=df, subset=(ID != i))
m3 <- gam(Volume ~ s(Girth) + s(Height), data=df, subset=(ID != i))
# looping for predictions:
df[df$ID==i, "pred1"] <- predict(m1, df[df$ID==i, ], type="response")
df[df$ID==i, "pred2"] <- predict(m2, df[df$ID==i, ], type="response")
df[df$ID==i, "pred3"] <- predict(m3, df[df$ID==i, ], type="response")
}
# calculating residuals:
df$res1 <- with(df, Volume - pred1)
df$res2 <- with(df, Volume - pred2)
df$res3 <- with(df, Volume - pred3)
Model <- paste("m", 1:10, sep="") # creates a vector of model names.
# creating a vector of mean-square errors (MSE):
MSE <- with(df, c(
sum(res1^2) / nrow(df),
sum(res2^2) / nrow(df),
sum(res3^2) / nrow(df)
))
model.mse <- data.frame(Model, MSE, R2) # creates a data frame of model names, mean-square errors and coefficients of determination.
model.mse <- model.mse[order(model.mse$MSE), ] # rearranges the previous data frame in order of increasing mean-square errors.
I'd appreciate any help. This code takes several days if run on 30,000 different GAM models and 3 predictors. Thanks
r
edited Jan 18 at 19:18
dww
14.8k22655
asked Jan 18 at 19:08
LexoLexo
1
I'm trying to speed up a script that otherwise takes days to handle larger data sets. So, is there a way to completely vectorize the following script:
# k-fold cross validation
df <- trees # a data frame 'trees' from R.
df <- df[sample(nrow(df)), ] # randomly shuffles the data.
k <- 10 # Number of folds. Note k=nrow(df) in the leave-one-out cross validation.
folds <- cut(seq(from=1, to=nrow(df)), breaks=k, labels=FALSE) # creates unique numbers for k equally size folds.
df$ID <- folds # adds fold IDs.
df[paste("pred", 1:10, sep="")] <- NA # adds multiple columns "pred1"..."pred10" to speed up the following loop.
library(mgcv)
for(i in 1:k) {
# looping for different models:
m1 <- gam(Volume ~ s(Height), data=df, subset=(ID != i))
m2 <- gam(Volume ~ s(Girth), data=df, subset=(ID != i))
m3 <- gam(Volume ~ s(Girth) + s(Height), data=df, subset=(ID != i))
# looping for predictions:
df[df$ID==i, "pred1"] <- predict(m1, df[df$ID==i, ], type="response")
df[df$ID==i, "pred2"] <- predict(m2, df[df$ID==i, ], type="response")
df[df$ID==i, "pred3"] <- predict(m3, df[df$ID==i, ], type="response")
}
# calculating residuals:
df$res1 <- with(df, Volume - pred1)
df$res2 <- with(df, Volume - pred2)
df$res3 <- with(df, Volume - pred3)
Model <- paste("m", 1:10, sep="") # creates a vector of model names.
# creating a vector of mean-square errors (MSE):
MSE <- with(df, c(
sum(res1^2) / nrow(df),
sum(res2^2) / nrow(df),
sum(res3^2) / nrow(df)
))
model.mse <- data.frame(Model, MSE, R2) # creates a data frame of model names, mean-square errors and coefficients of determination.
model.mse <- model.mse[order(model.mse$MSE), ] # rearranges the previous data frame in order of increasing mean-square errors.
I'd appreciate any help. This code takes several days if run on 30,000 different GAM models and 3 predictors. Thanks
r
r
edited Jan 18 at 19:18
dww
14.8k22655
asked Jan 18 at 19:08
LexoLexo
1
edited Jan 18 at 19:18
dww
14.8k22655
asked Jan 18 at 19:08
LexoLexo
1
edited Jan 18 at 19:18
dww
14.8k22655
edited Jan 18 at 19:18
dww
14.8k22655
edited Jan 18 at 19:18
dww
14.8k22655
14.8k22655
asked Jan 18 at 19:08
LexoLexo
1
asked Jan 18 at 19:08
LexoLexo
1
asked Jan 18 at 19:08
LexoLexo
1
1
1
How long does each GAM model take? Not convinced the for loop is your problem.
– dww
Jan 18 at 19:22
Yes, profile your code and you'll see the time is spent fitting the models. Your best option is parallelization.
– Roland
Jan 18 at 23:15
Thanks! Could you please help with re-writing the script into sapply() or foreach()/doParallel format?
– Lexo
Jan 21 at 11:11
add a comment |
1
How long does each GAM model take? Not convinced the for loop is your problem.
– dww
Jan 18 at 19:22
Yes, profile your code and you'll see the time is spent fitting the models. Your best option is parallelization.
– Roland
Jan 18 at 23:15
Thanks! Could you please help with re-writing the script into sapply() or foreach()/doParallel format?
– Lexo
Jan 21 at 11:11
1
1
How long does each GAM model take? Not convinced the for loop is your problem.
– dww
Jan 18 at 19:22
How long does each GAM model take? Not convinced the for loop is your problem.
– dww
Jan 18 at 19:22
Yes, profile your code and you'll see the time is spent fitting the models. Your best option is parallelization.
– Roland
Jan 18 at 23:15
Yes, profile your code and you'll see the time is spent fitting the models. Your best option is parallelization.
– Roland
Jan 18 at 23:15
Thanks! Could you please help with re-writing the script into sapply() or foreach()/doParallel format?
– Lexo
Jan 21 at 11:11
Thanks! Could you please help with re-writing the script into sapply() or foreach()/doParallel format?
– Lexo
Jan 21 at 11:11
add a comment |
0
active
oldest
votes
Your Answer
StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
draft saved
draft discarded
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f54260087%2fvectorizing-a-for-loop-for-cross-validation-in-r%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
0
active
oldest
votes
0
active
oldest
votes
active
oldest
votes
active
oldest
votes
draft saved
draft discarded
Thanks for contributing an answer to Stack Overflow!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
draft saved
draft discarded
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f54260087%2fvectorizing-a-for-loop-for-cross-validation-in-r%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
1
How long does each GAM model take? Not convinced the for loop is your problem.
– dww
Jan 18 at 19:22
Yes, profile your code and you'll see the time is spent fitting the models. Your best option is parallelization.
– Roland
Jan 18 at 23:15
Thanks! Could you please help with re-writing the script into sapply() or foreach()/doParallel format?
– Lexo
Jan 21 at 11:11