Add 2 Parker figs

Author: joa-quim

_assets/Parker_grav.png

@@ -1,50 +1,38 @@
 - **N** or **dimensions** or **inquire** : -- _dimensions=[**a**|**f**|**m**|**r**|**s**|*nx/ny*][**+a**|**d**|**h**|**l**][**+e**|**n**|**m**][**+t**_width_][**+v**][**+w**[_suffix_]][**+z**[**p**]]_\
-    Choose or inquire about suitable grid dimensions for FFT and set
-    optional parameters. Control the FFT dimension via these directives:
-
-    - **a** - Let the FFT select dimensions yielding the most accurate result.
-    - **f** - Force the FFT to use the actual dimensions of the data.
-    - **m** - Let the FFT select dimensions using the least work memory.
-    - **r** - Let the FFT select dimensions yielding the most rapid calculation.
-    - **s** - Just present a list of optional dimensions, then exit.
-
-    Without a directive we expect **-N**\ *nx/ny* which will do FFT on array size *nx/ny*
-    (must be >= grid file size). Default chooses dimensions >= data which optimize speed
-    and accuracy of FFT. If FFT dimensions > grid file dimensions, data are extended and
-    tapered to zero.
-
-    Control detrending of data by appending a modifier for removing a linear trend.
-    Consult module documentation for the default action:
-
-    - **+d** - Detrend data, i.e. remove best-fitting linear trend.
-    - **+a** - Only remove the mean value.
-    - **+h** - Only remove the mid value, i.e. 0.5 * (max + min).
-    - **+l** - Leave data alone.
-
-    Control extension and tapering of data by appending a modifier to control how
-    the extension and tapering are to be performed:
-
-    - **+e** - Extend the grid by imposing edge-point symmetry [Default].
-    - **+m** - Extends the grid by imposing edge mirror symmetry.
-    - **+n** - Turns off data extension.
-
-    Tapering is performed from the data edge to the FFT grid edge [100%].
-    Change this percentage via modifier **+t**\ *width*. When **+n** is in effect,
-    the tapering is applied instead to the data margins as no extension is
-    available [0%].
-
-    Control messages being reported:
-
-    - **+v** - Report suitable dimensions during processing.
-
-    Control writing of temporary results:
-    For detailed investigation you can write the intermediate grid being passed
-    to the forward FFT; this is likely to have been detrended, extended by
-    point-symmetry along all edges, and tapered. Use these modifiers to ave such grids:
-
-    - **+w** - Set the *suffix* from which output file name(s) will be created
-      (i.e., *ingrid_prefix.ext*) [Default is "tapered"], where *ext* is your file extension
-    - **+z** -  Save the complex grid produced by the forward FFT. By default we
-      write the real and imaginary components to *ingrid*\ \_real.\ *ext* and
-      *ingrid*\ \_imag.\ *ext*.  Append **p** to instead use the polar form of magnitude
-      and phase to files *ingrid*\ \_mag.\ *ext* and *ingrid*\ \_phase.\ *ext*.
+  Choose or inquire about suitable grid dimensions for FFT and set
+  optional parameters. Control the FFT dimension via these directives:
+  - **a** - Let the FFT select dimensions yielding the most accurate result.
+  - **f** - Force the FFT to use the actual dimensions of the data.
+  - **m** - Let the FFT select dimensions using the least work memory.
+  - **r** - Let the FFT select dimensions yielding the most rapid calculation.
+  - **s** - Just present a list of optional dimensions, then exit.
+  Without a directive we expect **N**_nx/ny_ which will do FFT on array size *nx/ny*
+  (must be >= grid file size). Default chooses dimensions >= data which optimize speed
+  and accuracy of FFT. If FFT dimensions > grid file dimensions, data are extended and
+  tapered to zero.\
+  Control detrending of data by appending a modifier for removing a linear trend.
+  Consult module documentation for the default action:
+  - **+d** - Detrend data, i.e. remove best-fitting linear trend.
+  - **+a** - Only remove the mean value.
+  - **+h** - Only remove the mid value, i.e. 0.5 * (max + min).
+  - **+l** - Leave data alone.
+  Control extension and tapering of data by appending a modifier to control how
+  the extension and tapering are to be performed:
+  - **+e** - Extend the grid by imposing edge-point symmetry [Default].
+  - **+m** - Extends the grid by imposing edge mirror symmetry.
+  - **+n** - Turns off data extension.
+  Tapering is performed from the data edge to the FFT grid edge [100%].
+  Change this percentage via modifier **+t**_width_. When **+n** is in effect,
+  the tapering is applied instead to the data margins as no extension is available [0%].\
+  Control messages being reported:
+  - **+v** - Report suitable dimensions during processing.
+  Control writing of temporary results:
+  For detailed investigation you can write the intermediate grid being passed
+  to the forward FFT; this is likely to have been detrended, extended by
+  point-symmetry along all edges, and tapered. Use these modifiers to ave such grids:
+  - **+w** - Set the *suffix* from which output file name(s) will be created
+    (i.e., *ingrid_prefix.ext*) [Default is "tapered"], where *ext* is your file extension
+  - **+z** -  Save the complex grid produced by the forward FFT. By default we
+    write the real and imaginary components to *ingrid_real.ext* and
+    *ingrid_imag.ext*.  Append **p** to instead use the polar form of magnitude
+    and phase to files *ingrid_mag.ext* and *ingrid_phase.ext*.

_assets/Parker_mag.png

@@ -59,21 +59,15 @@ Optional Arguments
 
 - **F** or **field** : -- *field=(faa=true, slab=true, far_field=true, bouguer=true, geoid=true, vgg=true, east=true, north=true)*\
     Specify desired geopotential field: compute geoid rather than gravity
-
-    -  **faa** = Free-air anomalies (mGal) [Default]. Add **slab=true** to add in the slab
+    - **faa** = Free-air anomalies (mGal) [Default]. Add **slab=true** to add in the slab
        implied when removing the mean value from the topography.  This requires zero topography
        to mean no mass anomaly. Alternatively, to force the far-field to be exactly zero
        (i.e., the corner nodes of the grid), select **far_field=true** instead.
-
-    -  **bouguer** = Bouguer gravity anomalies (mGal).
-
-    -  **geoid** = Geoid anomalies (m).
-
-    -  **vgg** = Vertical Gravity Gradient (VGG; 1 Eotvos = 0.1 mGal/km).
-
-    -  **east** = East deflections of the vertical (micro-radian).
-
-    -  **north** = North deflections of the vertical (micro-radian).
+    - **bouguer** = Bouguer gravity anomalies (mGal).
+    - **geoid** = Geoid anomalies (m).
+    - **vgg** = Vertical Gravity Gradient (VGG; 1 Eotvos = 0.1 mGal/km).
+    - **east** = East deflections of the vertical (micro-radian).
+    - **north** = North deflections of the vertical (micro-radian).
 
 \textinput{common_opts/opt_save_grd}
 
@@ -171,9 +165,9 @@ Examples
 ```julia
 using GMT, FFTW
 
-G = grdcut("@earth_relief_10m", region=(-12.5,-10,35.5,37.5));
+G = grdcut("@earth_relief_02m", region=(-12.5,-10,35.5,37.5));
 G2 = gravfft(G, density=1700, field=(faa=6, slab=4), f=:g);
-imshow(G2)
+imshow(G2, colorbar=true)
 ```
 \end{examplefig}
 

_assets/common_opts/explain_fft.md

@@ -69,7 +69,6 @@ Example
 A synthetic example. Make a Kaba like magnetization distribution of 10 A/m, compute the
 magnetic field created by it and invert this field.
 
-\begin{examplefig}{}
 ```julia
 using GMT, FFTW
 
@@ -96,7 +95,10 @@ grdimage!(Gbat_inv, figsize=7, xshift=-9, yshift=-9.0, title="Calculated Interfa
 grdimage!(Gres, figsize=7, xshift=9, title="Residues (mGal)", cmap=:auto,
           contour=true, colorbar=true, show=true)
 ```
-\end{examplefig}
+
+~~~
+<img src="/assets/Parker_grav.png" width="1000" class="center"/>
+~~~
 
 See Also
 --------

documentation/modules/gravfft.md

@@ -73,7 +73,6 @@ Example
 A synthetic example. Make a Kaba like magnetization distribution of 10 A/m, compute the
 magnetic field created by it and invert this field.
 
-\begin{examplefig}{}
 ```julia
 using GMT, FFTW
 
@@ -85,10 +84,12 @@ f3d = parkermag(Gm,  Gh, "dir", year=2000, thickness=1, pct=0);
 m3d = parkermag(f3d, Gh, "inv", year=2000, thickness=1, pct=0);
 
 grdimage(f3d, figsize=6, title="Field (nT)", colorbar=true)
-C = makecpt(m3d);		# Need a different colormap for the magnetization
-grdview!(f3d, figsize=6, zsize=4, view=(210, 40), title="Magnetization (A/m)", cmap=C, surf=:image, B=:za, xshift=8, show=true)
+grdview!(m3d, figsize=6, zsize=4, view=(210, 40), title="Magnetization (A/m)", cmap=:auto, surf=:image, B=:za, xshift=8, show=true)
 ```
-\end{examplefig}
+
+~~~
+<img src="/assets/Parker_mag.png" width="900" class="center"/>
+~~~
 
 
 See Also