This tutorial will show how you can start the FastRet GUI and explain the features it provides.
Starting the GUITo start the GUI, install the package and then run the following command in an interactive R terminal:
After running the above code, you should see an output like
Listening on http://localhost:8080
in your R console. This means that the GUI is now running and you can access it via the URL http://localhost:8080 in your browser. If your terminal supports it, you can also click on the displayed link.
By default, the GUI opens in mode Train new Model. To apply or adjust pretrained models, select mode Predict Retention Time or Adjust existing Model instead. For more information about the individual modes and the various input fields, click on the little question mark symbols next to the different input fields or read the following sections.
Train new ModelIn mode Train new Model you can upload excel files containing the names, SMILES and retention times of metabolites measured on your specific chromatography column and use this data to train a predictive model. FastRet includes an example Excel file with retention times for 442 metabolites measured on a reverse phase liquid chromatography column at a temperature of 35 degree celsius and a flowrate of 0.3ml/min. To print the file path of this excel file and a preview of its contents, enter the following lines an interactive R session:
path <- system.file("extdata", "RP.xlsx", package = "FastRet")
cat(path, "\n", sep = "")
#> /home/runner/work/_temp/Library/FastRet/extdata/RP.xlsx
df <- openxlsx::read.xlsx(path, 1)
head(df)
#> RT SMILES
#> 1 3.34 CCC(C(=O)O)O
#> 2 3.35 COC1=C(C=CC(=C1)CCN)O
#> 3 2.11 C1=NC2=C(N1)C(=NC=N2)N
#> 4 2.10 C1=NC2=C(C(=N1)N)N=CN2C3C(C(C(O3)COP(=O)(O)O)O)O
#> 5 3.13 C1C2C(C(C(O2)N3C=NC4=C3N=CN=C4N)O)OP(=O)(O1)O
#> 6 2.07 C1=NC2=C(C(=N1)N)N=CN2C3C(C(C(O3)COP(=O)(O)O)OP(=O)(O)O)O
#> NAME
#> 1 2-HYDROXYBUTYRIC ACID
#> 2 3-METHOXYTYRAMINE
#> 3 ADENINE
#> 4 ADENOSINE 5'-MONOPHOSPHATE
#> 5 ADENOSINE 3',5'-CYCLIC MONOPHOSPHATE
#> 6 ADENOSINE 3',5'-DIPHOSPHATE
To start model training, upload your Excel file and click the Train Model button. Training the model might take some time, depending on the size of the training set. When you click on Show console logs
you can see the progress of the training process. Upon completion, performance measures and a table of training dataset is shown. For further details about the training process and the performance measures, see section Model-Training of article Package-Internals.
To use the trained model to predict retention times for new molecules, you have to:
A more detailed guide on using the FastRet GUI for prediction is given in the next section Predict Retention Times.
Predict Retention TimesIn this mode, previously saved models can be used to make predictions for new data. To do so
If you have measured some metabolites on your new experiment setup that were also measured on the original setup, you can use this method to adjust your model for your new column. To do so, switch to mode Adjust existing Model and upload the model you want to adjust. Then upload an Excel file containing the retention times of the metabolites measured on your new column. The Excel file should contain columns NAME, SMILES and RT. After clicking the Adjust Model button, the model will be adjusted and you can use it to predict retention times for new molecules measured on your new column.
Selective MeasuringThis mode calculates, for a given data set, the best k molecules to be measured for a retention time prediction on a new experiment setup. It uses a combination of Ridge Regression and k-means to determine the best representatives of your dataset. Representatives as well as their corresponding clusters can be downloaded afterwards as an excel file. This step should be used once you have a predictive model and/or data set and want to adjust it to work for a new column with adjusted chromatographic properties such as gradient, temperature, etc.
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4