imported>Jeremy |
imported>Lyle |
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| ===Purpose=== | | ===Issue:=== |
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| Read an Experiment file and import corresponding files.
| | How are the error bars calculated for a regression model and can they be related to a confidence limit (confidence in the prediction)? |
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| ===Synopsis=== | | ===Possible Solutions:=== |
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| :x = experimentreadr(''filename'')
| | The error bars reported for inverse least squares models (and from the [[Ils_esterror]] function) represent the estimation error for each prediction, see: |
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| ===Description===
| | Faber, N.M. and Bro, R., Chemomem. and Intell. Syst., 61, 133-149 (2002) |
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| Experiment files include a list of data files and their corresponding
| | They can be read as a standard deviation of the estimate. However because the underlying distribution is not clearly known (and is a matter of research), a confidence limit is not reported. |
| "properties of interest" (y-values). An experiment file is expected to be
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| a plain text file or a Microsoft Excel-formatted file. The file should
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| consist of at least one column of text strings indicating the files to be
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| read and used as samples in the X-block of a regression or classification | |
| model and one column of numerical values indicating the values to use as
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| the corresponding y-block. If no experiment file filename is specified on | |
| the command line, the user is prompted to locate a suitable file.
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| Once loaded, the experiment file can be manipulated, excluding samples
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| using the include field of the Row Labels tab, or y-block columns using
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| the include field of the Column Labels tab. Samples can be marked as in
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| the Calibration or Validation set using the Row Labels tab.
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| When all manipulations are complete, the user clicks the check-mark
| | '''Still having problems? Please contact our helpdesk at [mailto:helpdesk@eigenvector.com helpdesk@eigenvector.com]''' |
| toolbar button to import all the indicated files and automatically load
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| the experiment data into the Analysis GUI.
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| ====X-block File Formats====
| | [[Category:FAQ]] |
| The x-block files named can be in any standard readable
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| file format. However, experiment files do not currently allow for any
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| multi-file formats. Named files must contain only one sample (row) of
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| data per file.
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| ====Header Row====
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| An experiment file can include an optional header row for the
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| filenames and properties of interest. This row can contain text lables
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| which will be used to label the y-block columns (i.e. giving a text
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| description of the property of interest.)
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| ====Calibration/Validation====
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| Experiment files can also contain information
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| used to split the data into calibration and validation sets. To use this
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| feature, include an additional column with the keywords "Calibration" or
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| "Validation" next to each file. When the experiment is imported, the data
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| will be automatically loaded into the appropriate data blocks.
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| NOTE: other valid synonyms include (all are case insensitive)
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| :Calibration = Cal = C
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| :Validation = Val = V = Test = T
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| ===Example===
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| <tt>
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| filename,concentration,cal/val
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| file1.spc,13.2,cal
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| file2.spc,19.0,cal
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| file3.spc,5.3,cal
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| file4.spc,8.3,val
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| </tt>
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| The above experiment file would define an experiment with three samples with X-block data
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| stored in the indicated files and y-values of 13.2, 19.0, 5.3, and 8.3
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| (with a text description of the y-values as "concentration"). The first
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| three files would be used for calibration, the last file for validation.
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| ===See Also===
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| [[autoimport]], [[jcampreadr]], [[spcreadr]], [[xclreadr]] | |
Issue:
How are the error bars calculated for a regression model and can they be related to a confidence limit (confidence in the prediction)?
Possible Solutions:
The error bars reported for inverse least squares models (and from the Ils_esterror function) represent the estimation error for each prediction, see:
Faber, N.M. and Bro, R., Chemomem. and Intell. Syst., 61, 133-149 (2002)
They can be read as a standard deviation of the estimate. However because the underlying distribution is not clearly known (and is a matter of research), a confidence limit is not reported.
Still having problems? Please contact our helpdesk at helpdesk@eigenvector.com