[GRASS-dev] [GRASS GIS] #3385: Typo in the i.vi man page

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1

#3385: Typo in the i.vi man page
------------------------------+-------------------------
Reporter: micha | Owner: grass-dev@…
     Type: task | Status: new
Priority: normal | Milestone: 7.2.2
Component: Docs | Version: 7.2.0
Keywords: Vegetation Index | CPU: Unspecified
Platform: All |
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I think there's a small error in the equation for MSAVI2 in the man page
for i.vi.
Here's what appears:
MSAVI2 = (1/2)*(2(NIR+1)-sqrt((2*NIR+1)^2-8(NIR-red)))

Should be (incorrect parentheses):

MSAVI2 = (1/2)*(2*NIR+1-sqrt((2*NIR+1)^2-8(NIR-red)))

Can anyone verify?

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Ticket URL: <https://trac.osgeo.org/grass/ticket/3385&gt;
GRASS GIS <https://grass.osgeo.org>

2

#3385: Typo in the i.vi man page
--------------------------+------------------------------
  Reporter: micha | Owner: grass-dev@…
      Type: task | Status: new
  Priority: normal | Milestone: 7.2.2
Component: Docs | Version: 7.2.0
Resolution: | Keywords: Vegetation Index
       CPU: Unspecified | Platform: All
--------------------------+------------------------------

Comment (by micha):

I see that the source for MSAVI2 in i.vi is consistant with the docs. The
equation in the source is:

result=0.5*(2*(nirchan+1)-sqrt((2*nirchan+1)*(2*nirchan+1)-8*(nirchan-
redchan)));

whereas in:

Qi, J., Chehbouni, A., Huete, A.R., Kerr, Y.H., Sorooshian, S., 1994. A
Modified Soil Adjusted Vegetation Index. REMOTE SENS. ENVIRO 48,
119–126.

The MSAVI2 equation is slightly different. There it's 0.5*(2*nir + 1 -
sqrt(...))

??

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Ticket URL: <https://trac.osgeo.org/grass/ticket/3385#comment:1&gt;
GRASS GIS <https://grass.osgeo.org>

3

#3385: Typo in the i.vi man page
--------------------------+------------------------------
  Reporter: micha | Owner: grass-dev@…
      Type: task | Status: new
  Priority: normal | Milestone: 7.2.2
Component: Docs | Version: 7.2.0
Resolution: | Keywords: Vegetation Index
       CPU: Unspecified | Platform: All
--------------------------+------------------------------

Comment (by ychemin):

it might be a typo indeed.
can you correct the source code and submit a revision?

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Ticket URL: <https://trac.osgeo.org/grass/ticket/3385#comment:2&gt;
GRASS GIS <https://grass.osgeo.org>

4

#3385: Typo in the i.vi man page
--------------------------+------------------------------
  Reporter: micha | Owner: grass-dev@…
      Type: task | Status: new
  Priority: normal | Milestone: 7.2.3
Component: Docs | Version: 7.2.0
Resolution: | Keywords: Vegetation Index
       CPU: Unspecified | Platform: All
--------------------------+------------------------------

Comment (by neteler):

ping

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Ticket URL: <https://trac.osgeo.org/grass/ticket/3385#comment:4&gt;
GRASS GIS <https://grass.osgeo.org>

5

#3385: Typo in the i.vi man page
--------------------------+------------------------------
  Reporter: micha | Owner: grass-dev@…
      Type: task | Status: new
  Priority: normal | Milestone: 7.2.3
Component: Docs | Version: 7.2.0
Resolution: | Keywords: Vegetation Index
       CPU: Unspecified | Platform: All
--------------------------+------------------------------

Comment (by veroandreo):

In [changeset:"72549" 72549]:
{{{
#!CommitTicketReference repository="" revision="72549"
i.vi: corrected MSAVI2 equation according to
https://doi.org/10.1016/0034-4257(94)90134-1, see #3385
}}}

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3385#comment:5&gt;
GRASS GIS <https://grass.osgeo.org>

6

#3385: Typo in the i.vi man page
--------------------------+------------------------------
  Reporter: micha | Owner: grass-dev@…
      Type: task | Status: new
  Priority: normal | Milestone: 7.2.3
Component: Docs | Version: 7.2.0
Resolution: | Keywords: Vegetation Index
       CPU: Unspecified | Platform: All
--------------------------+------------------------------

Comment (by veroandreo):

In [changeset:"72552" 72552]:
{{{
#!CommitTicketReference repository="" revision="72552"
i.vi: corrected MSAVI2 equation according to
https://doi.org/10.1016/0034-4257(94)90134-1, see #3385 (trunk, r72549)
}}}

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3385#comment:6&gt;
GRASS GIS <https://grass.osgeo.org>

7

#3385: Typo in the i.vi man page
--------------------------+------------------------------
  Reporter: micha | Owner: grass-dev@…
      Type: task | Status: closed
  Priority: normal | Milestone: 7.2.3
Component: Docs | Version: 7.2.0
Resolution: fixed | Keywords: Vegetation Index
       CPU: Unspecified | Platform: All
--------------------------+------------------------------
Changes (by veroandreo):

* status: new => closed
* resolution: => fixed

Comment:

In [changeset:"72554" 72554]:
{{{
#!CommitTicketReference repository="" revision="72554"
i.vi: corrected MSAVI2 equation according to
https://doi.org/10.1016/0034-4257(94)90134-1, fix #3385 (trunk, r72549)
}}}

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Ticket URL: <https://trac.osgeo.org/grass/ticket/3385#comment:7&gt;
GRASS GIS <https://grass.osgeo.org>