View source for Baseline correction with trendtool

===Baseline Corrected Area with TrendTool===
This page describes how to calculate the baseline corrected area using the trendtool.
 

* from the command line, call the trend tool passing it your dataset.  In this example I am using the nir demo data.   

:trendtool(nir_data)  

* Zoom into peak of interest, in this case the peak at 1060, then select add marker and move the marker to the peak by left clicking and dragging.
* Right click the marker, and select area. A second marker will appear. 
* Right click either of the markers and select add reference. A dashed line will appear.
* Right click the reference point, and select Baseline. A second dashed line will appear.
* Drag the dashed lines to the desired points to use for two-point baseline correction.
* Now take a look at the second figure. Because the dataset consisted of 10 spectra, the second figure plots the area under the curve and above the baseline for each of the 10 spectra in the dataset.


<gallery caption="Steps involved in calculating the Baseline Corrected Area" widths="400px" heights="300px" perrow="2">
File:add_marker_2.jpg|a)  ''zoom into peak of interested and select add marker''
File:area-2.jpg|b)  ''Right click the marker and select area''
File:second_marker_2.jpg|c)  ''A second marker will appear.  ''
File:add_reference_2.jpg|d)  ''select add reference, a dashed line will appear.''
File:add_baseline_2.jpg|e)  ''select add baseline, a second dashed line will appear.''
File:final_2.jpg|f)  ''drag the dashed lines to the desired points for two-point baseline correction''
File:calc_2.jpg|g)  ''area under the curve and above the baseline for each sample''
</gallery>