tidymodels | Easily install and load the tidymodels packages | Data Visualization library
kandi X-RAY | tidymodels Summary
kandi X-RAY | tidymodels Summary
tidymodels is a “meta-package” for modeling and statistical analysis that share the underlying design philosophy, grammar, and data structures of the tidyverse.
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Trending Discussions on tidymodels
QUESTION
I'm doing NLP with the tidymodels framework, taking advantage of the textrecipes package, which has recipe steps for text preprocessing. Here, step_tokenize
takes a character vector as input and returns a tokenlist
object. Now, I want to perform spell checking on the new tokenized variable with a custom function for correct spelling, using functions from the hunspell package, but I get the following error (link to the spell check blog post):
ANSWER
Answered 2021-Nov-18 at 17:58There isn't a canonical way to do this using {textrecipes} yet. We need 2 things, a function that takes a vector of tokens and returns spell-checked tokens (you provided that) and a way to apply that function to each element of the tokenlist
. For now, there isn't a general step that lets you do that, but you can cheat it by passing the function to custom_stemmer
in step_stem()
. Giving you the results you want
QUESTION
I struggle with multilevel models and prepared a reproducible example to be clear.
Let's say I would like to predict the height of children after 12 months of follow_up, i.e. their height at month == 12, using the previous values obtained for the height, but also their previous values of weight, with such a dataframe.
...ANSWER
Answered 2022-Mar-20 at 08:27My first problem is that if I add "weight" (and its multiple values per ID) as a variable, I have the following error "boundary (singular) fit: see help('isSingular')" (even in my large dataset), while if I keep only variables with one value per patient (e.g. sex) I do not have this problem. Can anyone explain me why ?
This happens when the random effects structure is too complex to be supported by the data. Other than this it is usually not possible to identify exactly why this happens in some situations and not others. Basically the model is overfitted. A few things you can try are:
- centering the
month
variable - centering other numeric variables
- fitting the model without the correlation between random slopes and intercepts, by using
||
instead of|
There are also some related questions and answers here:
As for the 2nd question, it sounds like you want some kind of time series model. An autoregressive model such as AR(1) might be sufficient, but this is not supported by lme4
. You could try nmle
instead.
QUESTION
I've been trying follow the approach set out by Hadley Wickham for running multiple models in a nested data frame as per https://r4ds.had.co.nz/many-models.html
I've managed to write this code below to create the multiple linear models:
...ANSWER
Answered 2022-Feb-09 at 10:25You have to specify the relevant arguments inside map
. There are two possibilities:
QUESTION
I want to use purrr::map_* functions to extract info from multiple models involving linear regression method. I am first creating some random dataset. The dataset has three dependent variables, and one independent variable.
...ANSWER
Answered 2022-Jan-20 at 08:40The list_tidymodels
needs to be created with list()
and not with c()
.
QUESTION
I'm new to tidymodels but apparently the step_pca()
arguments such as nom_comp
or threshold
are not being implemented when being trained. as in example below, I'm still getting 4 component despite setting nom_comp = 2
.
ANSWER
Answered 2022-Jan-11 at 14:56If you bake
the recipe it seems to work as intended but I don't know what you aim to achieve afterward.
QUESTION
I'm trying to preform PCA (principal component analysis) using TidyModels. I have created a recipe but I don't know how can I change the default rotation used in `step_pca() method (such as changing it to say Varimax rotation). any ideas?
this is my recipe:
...ANSWER
Answered 2022-Jan-10 at 17:51The step_pca()
function uses stats::prcomp()
under the hood, which I don't believe supports that, but you can get out the loadings using tidy()
and the type = "coef"
argument and then apply a rotation yourself. See this Cross Validated answer for more info.
QUESTION
I'm trying to figure out how step_dummy()
from recipes
package wrangles the data. Although there's a reference page for this function, I'm still unable to wrap my head around how to do it using "regular" tidyverse
tools I know. Here's some code based on recipes
and rsample
packages. I would like to achieve the same data output but just using dplyr
/tidyr
tools.
I chose diamonds
dataset from ggplot2
for this demonstration.
ANSWER
Answered 2021-Dec-16 at 15:57This is only a half answer, but this should help you see how the cut_*
columns are mapped out. Try this link for a more detailed look:https://recipes.tidymodels.org/articles/Dummies.html
QUESTION
I want to use xgboost
for a classification problem, and two predictors (out of several) are binary columns that also happen to have some missing values. Before fitting a model with xgboost
, I want to replace those missing values by imputing the mode in each binary column.
My problem is that I want to do this imputation as part of a tidymodels
"recipe". That is, not using typical data wrangling procedures such as dplyr
/tidyr
/data.table
, etc. Doing the imputation within a recipe should guard against "information leakage".
Although the recipes
package provides many step_*()
functions that are designed for data preprocessing, I could not find a way to do the desired imputation by mode on numeric binary columns. While there is a function called step_impute_mode()
, it accepts only nominal variables (i.e., of class factor
or character
). But I need my binary columns to remain numeric so they could be passed to the xgboost
engine.
Consider the following toy example. I took it from this reference page and changed the data a bit to reflect the problem.
create toy data
...ANSWER
Answered 2021-Dec-25 at 07:37Credit to user @gus who answered here:
QUESTION
I know that in tidymodels
you can set a custom tunable parameter space by interacting directly with the workflow object as follows:
ANSWER
Answered 2021-Aug-17 at 19:57The parameter ranges are inherently separated from the model specification and recipe specification in tidymodels. When you set tune()
you are giving a signal to the tune function that this parameter will take multiple values and should be tuned over.
So as a short answer, you can not specify ranges of parameters when you specify a recipe or a model, but you can create the parameters object right after as you did.
In the end, you need the parameter set to construct the grid values that you are using for hyperparameter tuning, and you can create those gid values in at least 4 ways.
The first way is to do it the way you are doing it, by pulling the needed parameters out of the workflow and modifying them when needed.
The second way is to create a parameters object that will match the parameters that you will need to use. This option and the remaining require you to make sure that you create values for all the parameters you are tuning.
The Third way is to skip the parameters object altogether and create the grid with your grid_*()
function and dials functions.
The fourth way is to skip dials functions altogether and create the data frame yourself. I find tidyr::crossing()
an useful replacement for grid_regular()
. This way is a lot easier when you are working with integer parameters and parameters that don't benefit from transformations.
QUESTION
As I want to produce some visualizations and analysis on forecasted data outside the modeltime framework, I need to extract confidence values, fitted values and maybe also residuals.
The documentation indicates, that I need to use the function modeltime_calibrate() to get the confidence values and residuals. So one question would be, where do I extract the fitted values from?
My main question is whatsoever, how to do calibration on recursive ensembles. For any non-ensemble model I was able to do it, but in case of recursive ensembles I encounter some error messages, if I want to calibrate.
To illustrate the problem, look at the example code below, which ends up failing to calibrate all models:
...ANSWER
Answered 2021-Dec-01 at 11:13The problem lies in your recursive_ensemble_panel
. You have to do the recursive part on the models themselves and not the ensemble. Like you I would have expected to do the recursive in one go, maybe via modeltime_table
.
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