3 ms·

One itch which (curiously) I can't seem to quite scratch in LaTeX is that it should be possible to say "plot equation \ref{eq:smth} for X in (-4,4)" and just ge

One itch which (curiously) I can't seem to quite scratch in LaTeX is that it should be possible to say "plot equation \ref{eq:smth} for X in (-4,4)" and just get the bloody graph. Why should I need to define the equation again in a separate place, perhaps even in a separate file?

kccqzy 8y ago
LaTeX doesn't have enough information about what your notations mean. You can very well write nonsensical formulas that look pretty in LaTeX but are absolutely meaningless.
- bingerman 8y ago
  I wish I had read the texbook or something similar sooner to gain knowledge like this. Used latex for years without knowing the basics and I regret that a lot. Also, (v)phantom and smash are something I really should have learned before all those fancy packages, nowadays I'm mostly using context anyways.
Wookai 8y ago
It's not exactly what you want, but you can do parametrized plots in TikZ to plot a given function for some range: http://www.texample.net/tikz/examples/parameterized-plots/ http://www.texample.net/tikz/examples/parameterized-plots/. I wouldn't be surprised if someone wrote a tool that allows you to use a reference to an equation as the function to plot :).
dmlorenzetti 8y ago
This is not what you asked for, since it still requires a separate file. However it might be close enough to what you want, and -- for complicated expressions -- possibly even better. You can write (or derive) the expression using sympy, then have sympy generate a numpy expression that can be evaluated. Sympy can also generate the LaTeX code for any expression. So while that isn't an in-LaTeX solution, it may be close to what you want. Johansson's "Numerical Python" shows several examples of this. I will scavenge one of his examples below (trusting it falls under "fair use", and hoping I transcribe it correctly -- note I have left out the imports). The example uses sympy to generate and plot Taylor series expansions of sin(x). The key bit to look for in the example is `sympy.lambdify()`. sym_x = sympy.Symbol("x") x = np.linspace(-2 * np.pi, 2 * np.pi, 100) def sin_expansion(x, n): return sympy.lambdify(sym_x, sympy.sin(sym_x).series(n=n+1).removeO(), 'numpy')(x) fig, ax = plt.subplots() ax.plot(x, np.sin(x), linewidth=4, color="red", label='exact') colors = ["blue", "black"] linestyles = [':', '-.', '--'] for idx, n in enumerate(range(1, 12, 2)): ax.plot(x, sin_expansion(x, n), color=colors[idx // 3], linestyle=linestyles[idx % 3], linewidth=3, label="order %d approx." % (n+1)) ax.set_ylim(-1.1, 1.1) ax.set_xlim(-1.5*np.pi, 1.5*np.pi) ax.legend(bbox_to_anchor=(1.02, 1), loc=2, borderaxespad=0.0) fig.subplots_adjust(right=.75) I highly recommend the book. It's full of nuggets like this.
deleted 8y ago
[deleted]

kccqzy 8y ago

LaTeX doesn't have enough information about what your notations mean. You can very well write nonsensical formulas that look pretty in LaTeX but are absolutely meaningless.

bingerman 8y ago
I wish I had read the texbook or something similar sooner to gain knowledge like this. Used latex for years without knowing the basics and I regret that a lot. Also, (v)phantom and smash are something I really should have learned before all those fancy packages, nowadays I'm mostly using context anyways.

Wookai 8y ago

It's not exactly what you want, but you can do parametrized plots in TikZ to plot a given function for some range: http://www.texample.net/tikz/examples/parameterized-plots/ http://www.texample.net/tikz/examples/parameterized-plots/. I wouldn't be surprised if someone wrote a tool that allows you to use a reference to an equation as the function to plot :).

dmlorenzetti 8y ago

This is not what you asked for, since it still requires a separate file. However it might be close enough to what you want, and -- for complicated expressions -- possibly even better. You can write (or derive) the expression using sympy, then have sympy generate a numpy expression that can be evaluated. Sympy can also generate the LaTeX code for any expression. So while that isn't an in-LaTeX solution, it may be close to what you want. Johansson's "Numerical Python" shows several examples of this. I will scavenge one of his examples below (trusting it falls under "fair use", and hoping I transcribe it correctly -- note I have left out the imports). The example uses sympy to generate and plot Taylor series expansions of sin(x). The key bit to look for in the example is `sympy.lambdify()`. sym_x = sympy.Symbol("x") x = np.linspace(-2 * np.pi, 2 * np.pi, 100) def sin_expansion(x, n): return sympy.lambdify(sym_x, sympy.sin(sym_x).series(n=n+1).removeO(), 'numpy')(x) fig, ax = plt.subplots() ax.plot(x, np.sin(x), linewidth=4, color="red", label='exact') colors = ["blue", "black"] linestyles = [':', '-.', '--'] for idx, n in enumerate(range(1, 12, 2)): ax.plot(x, sin_expansion(x, n), color=colors[idx // 3], linestyle=linestyles[idx % 3], linewidth=3, label="order %d approx." % (n+1)) ax.set_ylim(-1.1, 1.1) ax.set_xlim(-1.5*np.pi, 1.5*np.pi) ax.legend(bbox_to_anchor=(1.02, 1), loc=2, borderaxespad=0.0) fig.subplots_adjust(right=.75) I highly recommend the book. It's full of nuggets like this.

deleted 8y ago

[deleted]