obkh

Author: joa-quim

documentation/modules/gmtgravmag3d.md

@@ -21,3 +21,144 @@ Required Arguments (not all)
     are assumed constant (controlled by **density** or **mag_params**). Following cases are: 4 columns -> 4rth col
     magnetization intensity; 5 columns: mag, mag dip; 6 columns: mag, mag dec, mag dip; 8 columns: field dec, field dip,
     mag, mag dec, mag dip.  When n columns > 3 the third argument of the **mag_params** option is ignored.
+
+- **arg1** : In alternative to `fname` pass in a Mx3 matrix or a \myreflink{GMTdataset} with at least 3 columns.
+    `arg1` can also be a \myreflink{GMTfv} type like those produced by the _solids_ functions (\myreflink{sphere}, etc)
+    but it must be one made of triangles. That is, the output of \myreflink{cube} wont work because the body is
+    made out of quadrangles. Note, if the **body** option is used neither this option nor **fname** are used.
+
+- **C** or **density** : -- *density=??*\
+    Sets body density in _SI_. Append either a constant, the name of a grid file or a \myreflink{GMTgrid}
+    grid with variable densities. This option is mutually exclusive with **mag_params**
+
+- **H** or **mag_params** : -- *mag_params=f_dec/f_dip/m_int/m_dec/m_dip*\
+    Sets parameters for computing a magnetic anomaly. Use *f_dec*/*f_dip* to set the geomagnetic
+    declination/inclination in degrees. *m_int*/*m_dec*/*m_dip* are the body magnetic intensity
+    declination and inclination.
+
+- **F** or **track** : -- *track=xy_loc*\
+    Provide *xy_loc* (file name or GMTdataset) locations where the anomaly will be computed. Note,
+    this option is mutually exclusive with the **save** option.
+
+\textinput{common_opts/opt_save_grd}
+
+- **M** or **body** : -- *body=shape,params* **|** *body=(shape=name, params=...)*\
+    (An alternative to **raw_triang** and **stl**). Create geometric bodies and compute their grav/mag effect.
+    Select among one or more of the following bodies, where *x0* & *y0* represent the horizontal coordinates
+    of the body center [default to 0,0 positive up], *npts* is the number of points that a circle is discretized
+    and *n_slices* apply when bodies are made by a pile of slices. For example Spheres and Ellipsoids are made of
+    *2 x n_slices* and Bells have *n_slices* [Default 5]. It is also possible to select more than one body.
+    For example **body**=*((shape=:prism, params="1/1/1/-5/-10/1"), (shape=:sphere, params="1/-5"))* computes
+    the effect of a prism and a sphere. Unfortunately there is no current way of selecting distinct densities
+    or magnetic parameters for each body.
+
+      - *bell,height/sx/sy/z0[/x0/y0/n_sig/npts/n_slices]* Gaussian of height *height* with characteristic
+         STDs *sx* and *sy*. The base width (at depth *z0*) is controlled by the number of sigmas (*n_sig*) [Default = 2]
+
+      - *cylinder,rad/height/z0[/x0/y0/npts/n_slices]* Cylinder of radius *rad* and height *height* and base at depth *z0*
+
+      - *cone,semi_x/semi_y/height/z0[/x0/y0/npts]* Cone of semi axes *semi_x/semi_y* height *height* and base at depth *z0*
+
+      - *ellipsoid,semi_x/semi_y/semi_z/z_center[/x0/y0/npts/n_slices]* Ellipsoid of semi axes *semi_x/semi_y/semi_z*
+         and center depth *z_center*
+
+      - *prism,side_x/side_y/side_z/z0[/x0/y0]* Prism of sides *x/y/z* and base at depth *z0*
+
+      - *pyramid,side_x/side_y/height/z0[/x0/y0]* Pyramid of sides *x/y* height *height* and base at depth *z0*
+
+      - *sphere,rad/z_center[/x0/y0/npts/n_slices]* Sphere of radius *rad* and center at depth *z_center*
+
+\textinput{common_opts/opt_R}
+
+- **Tv** or **index** : -- *index=vert_file* **|** *index=D*\
+    Gives name of a vertex file defining a closed surface. The file formats correspond to the output
+    of the \myreflink{triangulate} module. The form *raw_triang=D* means that we can also
+    pass the data as a \myreflink{GMTdataset}
+
+- **Tr** or **raw_triang** : -- *raw_triang=raw_file* **|** *raw_triang=D*\
+    A *raw* format is a file with N rows (one per triangle) and 9 columns corresponding to the *x, y, z*
+    coordinates of each of the three vertex of each triangle. The form *raw_triang=D* means that we can also
+    pass the data as a \myreflink{GMTdataset}
+
+- **Ts** or **stl** or **STL** : -- *stl=raw_file*\
+    Alternatively, the **stl** option indicates that the surface file is in the ASCII STL
+    (Stereo Lithographic) format. These two type of files are used to provide a closed surface.
+
+- **noswap** or **no_swap** : -- *noswap=true*\
+    The closed surface formats (_STL_ or _raw_) are assumed to be provided with the facets (triangles)
+    following the counter-clockwise order. If that is not the case, _i.e._ they are clockwise oriented,
+    use this option to bring them to the expected order. However, this order may not be easy to check.
+    In case of doubt, compute the gravity anomaly caused by the body and see if it has the expected signal.
+
+Optional Arguments
+------------------
+
+- **E** or **thickness** : -- *thickness=??*\
+    Give layer thickness in m [Default = 0 m]. Use this option only when the triangles describe a non-closed
+    surface and you want the anomaly of a constant thickness layer.
+
+- **L** or **z_obs** or **observation_level** : -- -- *z_obs=0*\
+    sets level of observation [Default = 0]. That is the height (z) at which anomalies are computed.
+
+- **S** or **radius** : -- *radius=30*\
+    Set search radius in km (valid only in the two grids mode OR when **thickness**) [Default = 30 km].
+    This option serves to speed up the computation by not computing the effect of prisms that
+    are further away than *radius* from the current node.
+
+\textinput{common_opts/opt_V}
+
+**Z** or **level** or **reference_level** : -- *level=0*\
+    level of reference plane [Default = 0]. Use this option when the triangles describe a non-closed
+    surface and the volume is defined from each triangle and this reference level. An example will
+    be the water depth to compute a Bouguer anomaly.
+
+**Q** or **onebased** or **one_based** : -- *onebased=true*\
+    Use this option if the indices in file (**index**) is 1-based instead of the default (C) 0-based.
+    This option is needed when indices are 1-based, as likely is the case when bodies may have been
+    created in Julia.
+
+\textinput{common_opts/opt_f}
+   Geographic grids (dimensions of longitude, latitude) will be converted to
+   meters via a "Flat Earth" approximation using the current ellipsoid parameters.
+
+\textinput{common_opts/opt_h}
+
+\textinput{common_opts/opt__i}
+
+\textinput{common_opts/opt_o}
+
+\textinput{common_opts/opt__r}
+
+Grid Distance Units
+-------------------
+
+If the grid does not have meter as the horizontal unit, append **+u**\ *unit* to the input file name to convert from the
+specified unit to meter.  If your grid is geographic, convert distances to meters by supplying **f=:g** instead.
+
+Example
+-------
+
+To compute the magnetic anomaly of a cube of unit sides located at 5 meters depth and centered at -10,1 in a domain
+*R="-15/15/-15/15"* with a magnetization of 10 Am with a declination of 10 degrees, inclination of 60 in a magnetic field
+with -10 deg of declination and 40 deg of inclination, do:
+
+\begin{examplefig}{}
+```julia
+using GMT
+
+G = gravmag3d(region="-15/15/-15/15", I=0.1, mag_params="10/60/10/-10/40", body=(shape=:prism, params="1/1/1/-5/-10/1"));
+viz(G, colorbar=true)
+```
+\end{examplefig}
+
+See Also
+--------
+
+\myreflink{grdgravmag3d}, \myreflink{gravprisms}, talwani2d, talwani3d, \myreflink{triangulate}
+
+Reference
+---------
+
+Okabe, M., 1979, Analytical expressions for gravity anomalies due to
+polyhedral bodies and translation into magnetic anomalies, *Geophysics*,
+44, 730-741.

documentation/modules/grdgravmag3d.md

@@ -27,7 +27,6 @@ If two grids are provided then the gravity/magnetic effect of the volume between
     Provide *xy_loc* (file name or GMTdataset) locations where the anomaly will be computed. Note,
     this option is mutually exclusive with the **save** option.
 
-\textinput{common_opts/opt_save_grd}
 
 Optional Arguments
 ------------------