readme and license changes; small correction in loop_3d

In preparation for repository publication

+magnetic_field/loop_3d.m

@@ -118,8 +118,8 @@ function set_B0(h,B0)
             points(~good,:) = 0;            
             % calculate 2d derivatives and BR field (in local axes)
             [dBZ_dZ,dBZ_dR,dBR_dZ,dBR_dR] = h.derivatives_2d(Z,R);
-            [~,~,BR] = h.field_2d(Z,R);
-            BR_R(good) = BR(good)./R(good);
+            [~,~,BR_R] = h.field_2d(Z,R);
+            BR_R(good) = BR_R(good)./R(good);
             BR_R(~good) = dBR_dR(~good);            
             % Transform into global axes derivatives of the field. 
             Zx1 = h.axis(1); % escalar product 1Z*1x. These are the projections of Z and R versors along X,Y,Z.

LICENSE.md

@@ -1 +1,21 @@
-Copyright (c) 2017 Mario Merino. All rights reserved
+MIT License
+
+Copyright (c) 2017 Mario Merino
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -1,47 +1,89 @@
 MAGNETIC_FIELD
 ==============
 
-Magnetic field computations based on the analytical solution for coils and
+Magnetic field classes based on the analytical solution for coils and
 wire segments, in 2D and 3D.
 
+## Installation
+
+Installation requires simply that you 
+[download FUMAGNO](https://github.com/mariomerinomartinez/fumagno/archive/master.zip) 
+and add the base directory (the one that contains the `+fumagno` directory) to 
+your Matlab path.
+
+### Dependencies
+
+A recent version of Matlab is needed to run the code. 
+The code has been developed in Matlab 2016a Academic version. 
+
+MAGNETIC_FIELD 
+depends on other Matlab packages that you can download from my GitHub
+account:
+[utilities](https://github.com/mariomerinomartinez/utilities)
+and
+[constants_and_units](https://github.com/mariomerinomartinez/constants_and_units).
+These packages must be installed and added to your Matlab path beforehand.
+
+## Usage
+
 The code is structured into several Matlab classes as follows:
 
-- element,  element_2d, element_3d (abstract classes): all magnetic field
+* `element`,  `element_2d`, `element_3d` (abstract classes): all magnetic field
 generator elements inherit from these parent classes. Used to set some
 standard interfaces; not intended for direct usage by user. They also provide
 some commodity functions to calculate the field on a plane and to plot a field
 component on a plane.
+* `loop_2d`, `loop_3d`: analytical magnetic field of a single current loop of
+zero thickness, after solving the singularity for Br at the axis. The 2d
+version defines the magnetic streamfunction psi. The most thoroughly tested 
+classes.
+* `library_2d`, `library_3d`: allow to define some interpolation libraries for
+the fields and interpolate there. 
+* `path_3d`: the magnetic field of a wire defined by a set of nodes, computed
+in a step-wise manner with Biot-Savart's Law.  Not extensively tested yet;
+could contain errors.
+* `wire_2d`, `wire_3d`: the analytic magnetic field of a straight infinite 
+conductor. Not extensively tested yet; could contain errors.
+* `uniform_2d`, `uniform_3d`: a constant, uniform magnetic field in a given
+direction.
+* `array` (abstract class): sets the basic interfaces for arrays of generators 
+(i.e. collections of generator elements).
+* `array_2d`, `array_3d`: these are classes that allow collecting many
+generator elements in an array, and redefine some methods to compute field of
+all elements simultaneously. 
 
-* loop_2d, loop_3d: analytical magnetic field of a single current loop of zero
-thickness, after solving the singularity for Br at the axis. The 2d version
-defines the magnetic streamfunction psi. Inherit from element_2d and
-element_3d, respectively. Loop_3d, in addition, inherits from loop_2d.
+Usage is straight forward. Start by creating an object of the desired class and setting its parameters, then call one of its methods:
 
-* library_2d, library_3d: allows to define some interpolation libraries for
-the fields and interpolate there. Inherit from element_2d and element_3d,
-respectively.
+```Matlab
+mf = magnetic_field.loop_2d('RL',5,'I',10); % Create loop_2d object
+[psi,Bz,Br] = mf.field_2d(0,0); % query the field at z=0, r=0
+```
 
-* path_3d: the magnetic field of a wire defined by a set of nodes. Inherits
-from element_3d.
+### Testing
 
-* uniform_2d, uniform_3d: a constant, uniform magnetic field in a given
-direction. Inherit from element_2d and element_3d, respectively.
+Unit tests are found in the `/test` subdirectory. After adding the package to
+your Matlab path, you can run all tests by executing `runtests` from this 
+subdirectory.
 
-* array (abstract class): sets the basic interfaces for arrays of generators 
-(i.e. collections of generator elements). Inherits from element.
+## Contributing
 
-* array_2d, array_3d: these and 3d are classes that collect many generator
-elements in an array, and redefine some methods to compute field of all
-elements simultaneously. Inherit from array.
+If you have any comments for improvement or 
+are interested in contributing to the continued 
+development of this or any of my other codes, you can contact me 
+through my [personal website](http://mariomerino.uc3m.es/).
 
-Testing
--------
+## Acknowledging 
 
-Unit tests are found in the /test subdirectory. After adding the package to
-your Matlab path, you can run all tests by executing 'runtests' from this 
-subdirectory.
+This program is released as open source in the hope that it will be useful to
+other people. 
+
+If you find it useful and/or use it in any of your works, I kindly ask you
+to acknowledge it by citing [TBD] (preferred) 
+and/or by citing the code directly as: [TBD] 
+
+## License
 
-License
--------
+Copyright (c) 2017 Mario Merino. The software is released as open 
+source with the [MIT License](LICENSE.md).
 
-Copyright (c) 2017 Mario Merino. All rights reserved
+