similar to: R model developing & validating - Open to Discussion

Good morning, Sorry to trouble the list. I have a problem I hope to seek your advice on. Essentially, I am trying to 'validate' a multivariate Cox proportional hazards model built in a training set, by testing it on an external test set. I have performed a survfit using the Cox model to predict survival for the test set, and obtained individual predictions for survival time, with

Hello all, I have generated a principal components regression model using the pcr() function from the PLS package (R version 2.12.0). I am getting a "non-conformable arguments" error when I try to use the predict() function on new data, but only when I try to read in the new data from a separate file. More specifically, when my data looks like this #########training data

Sir, This query is related to randomForest regression using R. I have a dataset called qsar.arff which I use as my training set and then I run the following function - rf=randomForest(x=train,y=trainy,xtest=train,ytest=trainy,ntree=500) where train is a matrix of predictors without the column to be predicted(the target column), trainy is the target column.I feed the same data

Hello, I use nnet to do prediction for a continuous variable. after that, I calculate correlation coefficient between predicted value and real observation. I run my code(see following) several time, but I get different correlation coefficient each time. Anyone know why? In addition, How to calculate prediction accuracy for prediction of continuous variable? Aimin thanks, > m.nn.omega

Hi all, I run R 2.11.1 under ubuntu 10.10 and caret version 2.88. I use the caret package to compare different models on a dataset. In order to compare their different performances I would like to use the same data partitions for every models. I understand that using a LGOCV or a boot type re-sampling method along with the "index" argument of the trainControl function, one is able to

Dear all, Objective: I am trying to learn about neural networks. I want to see if i can train an artificial neural network model to discriminate between spam and nonspam emails. Problem: I created my own model (example 1 below) and got an error of about 7.7%. I created the same model using the Rattle package (example 2 below, based on rattles log script) and got a much better error of about

TL;DR; We can improve compiler optimizations driven by heuristics by replacing those heuristics with machine-learned policies (ML models). Policies are trained offline and ship as part of the compiler. Determinism is maintained because models are fixed when the compiler is operating in production. Fine-tuning or regressions may be handled by incorporating the interesting cases in the ML training

It turns out it's me, sorry. Let me see how I can sort this out. In the meantime, here is the csv: SPEC2006 data: binary,base -Oz size,ML -Oz size,ML size shrink by,,perf: base -Oz scores,perf: ML -Oz scores,ML improvement by 400.perlbench,2054200,2086776,-1.59%,,2.9,2.9,0.00% 401.bzip2,1129976,1095544,3.05%,,6.4,6.2,-3.13% 403.gcc,4078488,4130840,-1.28%,,11.6,11.7,0.86%

Dear R-friends, How do you test the goodness of prediction of a model, when you predict on a set of data DIFFERENT from the training set? I explain myself: you train your model M (e.g. glm,gam,regression tree, brt) on a set of data A with a response variable Y. You then predict the value of that same response variable Y on a different set of data B (e.g. predict.glm, predict.gam and so on).

+Yundi Qian <yundi at google.com> +Eugene Brevdo <ebrevdo at google.com> , our team members from the ML side. To avoid formatting issues, here is a link to the RFC <https://docs.google.com/document/d/1BoSGQlmgAh-yUZMn4sCDoWuY6KWed2tV58P4_472mDE/edit?usp=sharing>, open to comments. Thanks! On Wed, Apr 8, 2020 at 2:34 PM Mircea Trofin <mtrofin at google.com> wrote: >

Sorry, I wasn't aware of that. I can make the google doc view-only, keeping the current comments. I'll wait a bit (few hrs) to see if there's any pushback to that. On Thu, Apr 9, 2020 at 9:57 AM Xinliang David Li <xinliangli at gmail.com> wrote: > One suggestion : should we consolidate the discussion into the main > thread? I know some folks are not willing to comment in

Hi all: I'm developing an application in which I use standard data to train the model in LDA and use the trained model to predict on test data. I can't train the model every time when I do prediction. So I need to save the trained model onto disk after the first training. Does anybody have idea about this? You help is highly appreciated. Best Regards Feng

Hi, I am trying to construct a svmpoly model using the "caret" package (please see code below). Using the same data, without changing any setting, I am just changing the seed value. Sometimes it constructs the model successfully, and sometimes I get an ?Error in indexes[[j]] : subscript out of bounds?. For example when I set seed to 357 following code produced result only for 8

I would really like some or any advice on how I can improve (or fix??) the following analysis. I hope I have provided a completely runnable code - it doesn't produce any errors for me. The resulting plot at the end shows a pretty poor correlation (just speaking visually here) to the test set. How can I improve the performance of the mapping and prediction? Here are some of the data

Hello, I am having some trouble using a model I created from plsr (of train) to analyze each invididual R^2 of the 10 components against the test data. For example: mice1 <- plsr(response ~factors, ncomp=10 data=MiceTrain) R2(mice1) ##this provides the correct R2 for the Train data for 10 components ## Now my next objective is to calculate my model's R2 for each component on the

Does anyone know how to get the C-index from a logistic model - not using the dataset that was used to train the model, but instead using a fresh dataset on the same model? I have a dataset of 400 points that I've split into two halves, one for training the logistic model, and the other for evaluating it. The structure is as follows: column headers are "got a loan" (dichotomous),

Hi there, I've a training dataset and a test dataset. My aim is to visually allocate the test data within the calibrated space reassembled by the PC's of the training data set, furthermore to keep the training data set coordinates fixed, so they can serve as ruler for measurement for additional test datasets coming up. Please find a minimum working example using the wine dataset below.

Dear developers, I have jutst started working with caret and all the nice features it offers. But I just encountered a problem: I am working with a dataset that include 4 predictor variables in Descr and a two-category outcome in Categ (codified as a factor). Everything was working fine I got the results, confussion matrix etc. BUT for obtaining the AUC and predicted probabilities I had to add

Hi, I am using the validate function in the design library to get corrected Somer's Dxy for cox ph models. When my sample size is reduced from 300 to 150, the function complains (length of dimnames[1] not equal to array) and does not produce any results. There are no missing values in the data. Any suggestions for a work-around? Thank you in Advance. >

I would like to run a loop in R. I have never done this before, so I would be very grateful for your help ! 1. I have a sample set: 25 objects. I would like to draw 1 object from it and use it as a test set for my future external validation. The remaining 24 objects I would like to use as a training set (to select a model). I would like to repeat this process until all 25 objects are used as a