Python Forum

Hey Py community,
I'm writing down Markowitz's efficient frontier with jupy using the 4 significant cryptos as stocks and verything is fine until the plt.plot() function comes up. I've used three different methods and none of them fits the expected return/expected volatility graph.
The first one is a np.linspace() function.
Error 1:

ValueError Traceback (most recent call last)
<ipython-input-506-825222cab96e> in <module>
5 plt.colorbar(label='sharpe ratio')
6 plt.scatter(expectedVolatility[maxIndex],expectedReturn[maxIndex],c='red')
----> 7 plt.scatter(volatility_opt,returns)
8 plt.show()

C:\Anaconda3\lib\site-packages\matplotlib\pyplot.py in scatter(x, y, s, c, marker, cmap, norm, vmin, vmax, alpha, linewidths, verts, edgecolors, plotnonfinite, data, **kwargs)
2888 verts=cbook.deprecation._deprecated_parameter,
2889 edgecolors=None, *, plotnonfinite=False, data=None, **kwargs):
-> 2890 __ret = gca().scatter(
2891 x, y, s=s, c=c, marker=marker, cmap=cmap, norm=norm,
2892 vmin=vmin, vmax=vmax, alpha=alpha, linewidths=linewidths,

C:\Anaconda3\lib\site-packages\matplotlib\__init__.py in inner(ax, data, *args, **kwargs)
1445 def inner(ax, *args, data=None, **kwargs):
1446 if data is None:
-> 1447 return func(ax, *map(sanitize_sequence, args), **kwargs)
1448
1449 bound = new_sig.bind(ax, *args, **kwargs)

C:\Anaconda3\lib\site-packages\matplotlib\cbook\deprecation.py in wrapper(*inner_args, **inner_kwargs)
409 else deprecation_addendum,
410 **kwargs)
--> 411 return func(*inner_args, **inner_kwargs)
412
413 return wrapper

C:\Anaconda3\lib\site-packages\matplotlib\axes\_axes.py in scatter(self, x, y, s, c, marker, cmap, norm, vmin, vmax, alpha, linewidths, verts, edgecolors, plotnonfinite, **kwargs)
4439 y = np.ma.ravel(y)
4440 if x.size != y.size:
-> 4441 raise ValueError("x and y must be the same size")
4442
4443 if s is None:

ValueError: x and y must be the same size

The second one is a loop function
Error:
ValueError Traceback (most recent call last)
<ipython-input-107-189155ee8df1> in <module>
1 plt.figure(figsize=(20,6))
----> 2 plt.scatter(stds,returns)
3 plt.title('Efficient Frontier')
4 plt.xlabel('Portfolio std')
5 plt.ylabel('Porfolio returns')

C:\Anaconda3\lib\site-packages\matplotlib\pyplot.py in scatter(x, y, s, c, marker, cmap, norm, vmin, vmax, alpha, linewidths, verts, edgecolors, plotnonfinite, data, **kwargs)
2888 verts=cbook.deprecation._deprecated_parameter,
2889 edgecolors=None, *, plotnonfinite=False, data=None, **kwargs):
-> 2890 __ret = gca().scatter(
2891 x, y, s=s, c=c, marker=marker, cmap=cmap, norm=norm,
2892 vmin=vmin, vmax=vmax, alpha=alpha, linewidths=linewidths,

C:\Anaconda3\lib\site-packages\matplotlib\__init__.py in inner(ax, data, *args, **kwargs)
1445 def inner(ax, *args, data=None, **kwargs):
1446 if data is None:
-> 1447 return func(ax, *map(sanitize_sequence, args), **kwargs)
1448
1449 bound = new_sig.bind(ax, *args, **kwargs)

C:\Anaconda3\lib\site-packages\matplotlib\cbook\deprecation.py in wrapper(*inner_args, **inner_kwargs)
409 else deprecation_addendum,
410 **kwargs)
--> 411 return func(*inner_args, **inner_kwargs)
412
413 return wrapper

C:\Anaconda3\lib\site-packages\matplotlib\axes\_axes.py in scatter(self, x, y, s, c, marker, cmap, norm, vmin, vmax, alpha, linewidths, verts, edgecolors, plotnonfinite, **kwargs)
4439 y = np.ma.ravel(y)
4440 if x.size != y.size:
-> 4441 raise ValueError("x and y must be the same size")
4442
4443 if s is None:

ValueError: x and y must be the same size

The third one doesn't show any error but the graph with go.Figure() from plotly is blank.

Probably it's a question of dimension but no clue what to do to improve the values' and let them be represented.

Thanks in advance.