Update sig_sys_ex_03.tex, sig_sys_ex_03AddOn.tex, README.md

README.md

@@ -16,7 +16,7 @@ Sources (tex, ipynb) can be found at github
 
 The [Anaconda distribution](https://www.anaconda.com/distribution/) is a very convenient solution to install a required environment, i.e. to have access to the Jupyter Notebook renderer with a Python compiler on a personal computer. It is very likely that a very recent installation of Anaconda already delivers all required packages just using the `root` environment. We actually do not need very special packages. However, if `root` is not working immediately, creating and activating a dedicated environment `mydsp` might be useful. Do the following steps
 
-- get at least python 3.8x, numpy, scipy, matplotlib, notebook, jupyterlab, ipykernel, the other packages are very useful tools for convenience
+- get at least python 3.8x, numpy, sympy, scipy, matplotlib, notebook, jupyterlab, ipykernel, the other packages are very useful tools for convenience
 
 `conda create -n mydsp python=3.8 pip numpy scipy matplotlib notebook jupyterlab pydocstyle pycodestyle autopep8 flake8 ipykernel nb_conda jupyter_nbextensions_configurator jupyter_contrib_nbextensions`
 
@@ -38,7 +38,7 @@ The [Anaconda distribution](https://www.anaconda.com/distribution/) is a very co
 
 If the above steps still lead to problems, the following lines created the environment `mydsp`
 - using `conda 4.9.2`
-- `conda create -n mydsp python=3.8.6 pip=20.2.4 numpy=1.19.4 scipy=1.5.3 matplotlib=3.3.3 jupyter=1.0.0 notebook=6.1.5 jupyterlab=2.2.9 pydocstyle=5.1.1 pycodestyle=2.6.0 autopep8=1.5.4 flake8=3.8.4 ipykernel=5.3.4 nb_conda=2.2.1 jupyter_nbextensions_configurator=0.4.1 jupyter_contrib_nbextensions=0.5.1`
+- `conda create -n mydsp python=3.8.6 pip=20.2.4 numpy=1.19.4 sympy=1.7.1 scipy=1.5.3 matplotlib=3.3.3 jupyter=1.0.0 notebook=6.1.5 jupyterlab=2.2.9 pydocstyle=5.1.1 pycodestyle=2.6.0 autopep8=1.5.4 flake8=3.8.4 ipykernel=5.3.4 nb_conda=2.2.1 jupyter_nbextensions_configurator=0.4.1 jupyter_contrib_nbextensions=0.5.1`
 - `pip install soundfile`
 
 ## German Version

laplace_transform/fundamental_signals_laplace_plane_31AEFEF90B.ipynb

@@ -56,14 +56,14 @@
     "    ax = fig.gca(projection='3d')\n",
     "    Ncol = 20\n",
     "    col_tick = np.linspace(-30, 30, Ncol, endpoint=False)\n",
-    "    cmap = mpl.cm.get_cmap('plasma')\n",
+    "    cmap = mpl.cm.get_cmap('cividis')\n",
     "    norm = mpl.colors.BoundaryNorm(col_tick, cmap.N)\n",
     "    surf = ax.plot_surface(sigma, omega, xa,\n",
     "                           cmap=cmap,\n",
     "                           norm=norm,\n",
     "                           rstride=5, cstride=5, linewidth=0, alpha=1)\n",
     "    ax.plot3D(sigma[:, N//2], omega[:, N//2],\n",
-    "              xfta[:, N//2], 'C2', lw=3, alpha=1)\n",
+    "              xfta[:, N//2], 'darkred', lw=3, alpha=1)\n",
     "    cbar = fig.colorbar(\n",
     "        surf, ax=ax, ticks=col_tick[::Ncol//10], label=r'|X(s)| in dB')\n",
     "    ax.set_xlim(-10, 10)\n",