Updated README file.

README.do.txt

@@ -54,16 +54,31 @@ can be created by the program "`examples/pendulum.py`": "https://github.com/hplg
 ===== Technology =====
 
 Pysketcher applies Matplotlib to make the drawings, but it is quite
-easy to replace the backend `MatplotlibDraw.py` by similar code utilizing
-TikZ or another plotting package. The Pysketcher software is a thin
-layer basically constructing a tree structure of elements in the
-sketch. A lot of classes are offered for different type of basic
+easy to replace the backend `MatplotlibDraw.py` by similar code
+utilizing TikZ or another plotting package. The Pysketcher software is
+a thin layer basically constructing a tree structure of elements in
+the sketch. A lot of classes are offered for different type of basic
 elements, such as Circle, Rectangle, Text, Text with arrow, Force,
-arbitrary curve, etc.
-Complicated figures can be created by sticking one
-figure into another
-(i.e., hierarchical building of figures by sticking one tree
-structure into another).
+arbitrary curve, etc.  Complicated figures can be created by sticking
+one figure into another (i.e., hierarchical building of figures by
+sticking one tree structure into another).
+
+===== Install =====
+
+Pysketcher is pure Python code and
+works with Python version 2 and 3. Just do the standard
+
+!bc sys
+Terminal> sudo python setup.py install
+!ec
+
+Pysketcher demands installation of the following packages:
+
+ * Matplotlib (`sudp pip install matplotlib`)
+ * Future (`sudo pip install future`)
+ * NumPy (`sudo pip install numpy`)
+
+The `Spline` object in Pysketcher also requires SciPy (`sudo pip install scipy`).
 
 ===== Citation =====
 

README.md

@@ -12,23 +12,28 @@ Pysketcher can typically be used to draw figures like
 Such figures can easily be *interactively* made using a lot of drawing programs.
 A Pysketcher figure, however, is defined in terms of computer code. This gives
 a great advantage: geometric features can be parameterized in term
-of variables, as here:
+of variables. Geometric variations are then trivially generated, and
+complicated figures can be built as a hierarchy of simpler elements.
+
+Here is a very simple figure that illustrates how geometric features are
+parameterized by variables (H, R, L, etc.):
 
 <!-- <img src="doc/src/tut/fig-tut/vehicle0_dim.png" width=600> -->
 ![](doc/src/tut/fig-tut/vehicle0_dim.png)
 
-One can then quickly change parameters, here to
+One can then quickly change parameters, below to
 `R=0.5; L=5; H=2` and `R=2; L=7; H=1`, and get new figures that would be
 tedious to draw manually in an interactive tool.
 
 <!-- <img src="doc/src/tut/fig-tut/vehicle_v23.png" width=800> -->
 ![](doc/src/tut/fig-tut/vehicle_v23.png)
 
-Another major feature of Pysketcher is the ability to let animate the
-sketch. Here is an example of a very simple vehicle on a bumpy road,
+Another major feature of Pysketcher is the ability to let the
+sketch be dynamic and make an animation of the time evolution.
+Here is an example of a very simple vehicle on a bumpy road,
 where the solution of a differential equation (upper blue line) is fed
 back to the sketch to make a vertical displacement of the spring and
-other objects in the vehicle, [view animation](http://hplgit.github.io/bumpy/doc/src/mov-bumpy/m2_k1_5_b0_2/index.html) (the animation was created by
+other objects in the vehicle. [View animation](http://hplgit.github.io/bumpy/doc/src/mov-bumpy/m2_k1_5_b0_2/index.html) (the animation was created by
 [this Pysketcher script](https://github.com/hplgit/bumpy/blob/master/doc/src/fig-bumpy/bumpy_road_fig.py)).
 
 <!-- <img src="http://hplgit.github.io/bumpy/doc/src/mov-bumpy/m2_k1_5_b0_2/tmp_frame_0030.png" width=600> -->
@@ -54,16 +59,32 @@ can be created by the program [`examples/pendulum.py`](https://github.com/hplgit
 ### Technology
 
 Pysketcher applies Matplotlib to make the drawings, but it is quite
-easy to replace the backend `MatplotlibDraw.py` by similar code utilizing
-TikZ or another plotting package. The Pysketcher software is a thin
-layer basically constructing a tree structure of elements in the
-sketch. A lot of classes are offered for different type of basic
+easy to replace the backend `MatplotlibDraw.py` by similar code
+utilizing TikZ or another plotting package. The Pysketcher software is
+a thin layer basically constructing a tree structure of elements in
+the sketch. A lot of classes are offered for different type of basic
 elements, such as Circle, Rectangle, Text, Text with arrow, Force,
-arbitrary curve, etc.
-Complicated figures can be created by sticking one
-figure into another
-(i.e., hierarchical building of figures by sticking one tree
-structure into another).
+arbitrary curve, etc.  Complicated figures can be created by sticking
+one figure into another (i.e., hierarchical building of figures by
+sticking one tree structure into another).
+
+### Install
+
+Pysketcher is pure Python code and
+works with Python version 2 and 3. Just do the standard
+
+
+```
+Terminal> sudo python setup.py install
+```
+
+Pysketcher demands installation of the following packages:
+
+ * Matplotlib (`sudp pip install matplotlib`)
+ * Future (`sudo pip install future`)
+ * NumPy (`sudo pip install numpy`)
+
+The `Spline` object in Pysketcher also requires SciPy (`sudo pip install scipy`).
 
 ### Citation