plt.savefig 함수에서의 must be real number, not str 오류 발생

아래 캐글 코드를 돌려보다가, 그래프 사진을 저장하는 코드에서 'must be real number, not str'라는 오류가 발생하였다.

# https://www.kaggle.com/code/shivamb/semi-supervised-classification-using-autoencoders/notebook
def tsne_plot(x1, y1, name="graph.png"):
    tsne = TSNE(n_components=2, random_state=0)
    X_t = tsne.fit_transform(x1)

    plt.figure(figsize=(12, 8))
    plt.scatter(X_t[np.where(y1 == 0), 0], X_t[np.where(y1 == 0), 1], marker='o', color='g', linewidth='1', alpha=0.8, label='Non Fraud')
    plt.scatter(X_t[np.where(y1 == 1), 0], X_t[np.where(y1 == 1), 1], marker='o', color='r', linewidth='1', alpha=0.8, label='Fraud')

    plt.legend(loc='best');
    plt.savefig(name);
    plt.show();
    
tsne_plot(X, Y, "original.png")

 

 

▼ 오류 로그

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-21-38294f5ed148> in <cell line: 15>()
     13     plt.show();
     14 
---> 15 tsne_plot(X, Y, "original.png")

18 frames
<ipython-input-21-38294f5ed148> in tsne_plot(x1, y1, name)
     10     print(name)
     11     print(type(name))
---> 12     plt.savefig(name);
     13     plt.show();
     14 

/usr/local/lib/python3.10/dist-packages/matplotlib/pyplot.py in savefig(*args, **kwargs)
   1021 def savefig(*args, **kwargs):
   1022     fig = gcf()
-> 1023     res = fig.savefig(*args, **kwargs)
   1024     fig.canvas.draw_idle()  # Need this if 'transparent=True', to reset colors.
   1025     return res

/usr/local/lib/python3.10/dist-packages/matplotlib/figure.py in savefig(self, fname, transparent, **kwargs)
   3341                         ax.patch._cm_set(facecolor='none', edgecolor='none'))
   3342 
-> 3343             self.canvas.print_figure(fname, **kwargs)
   3344 
   3345     def ginput(self, n=1, timeout=30, show_clicks=True,

/usr/local/lib/python3.10/dist-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, pad_inches, bbox_extra_artists, backend, **kwargs)
   2364                 # force the figure dpi to 72), so we need to set it again here.
   2365                 with cbook._setattr_cm(self.figure, dpi=dpi):
-> 2366                     result = print_method(
   2367                         filename,
   2368                         facecolor=facecolor,

/usr/local/lib/python3.10/dist-packages/matplotlib/backend_bases.py in <lambda>(*args, **kwargs)
   2230                 "bbox_inches_restore"}
   2231             skip = optional_kws - {*inspect.signature(meth).parameters}
-> 2232             print_method = functools.wraps(meth)(lambda *args, **kwargs: meth(
   2233                 *args, **{k: v for k, v in kwargs.items() if k not in skip}))
   2234         else:  # Let third-parties do as they see fit.

/usr/local/lib/python3.10/dist-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs)
    507             *metadata*, including the default 'Software' key.
    508         """
--> 509         self._print_pil(filename_or_obj, "png", pil_kwargs, metadata)
    510 
    511     def print_to_buffer(self):

/usr/local/lib/python3.10/dist-packages/matplotlib/backends/backend_agg.py in _print_pil(self, filename_or_obj, fmt, pil_kwargs, metadata)
    455         *pil_kwargs* and *metadata* are forwarded).
    456         """
--> 457         FigureCanvasAgg.draw(self)
    458         mpl.image.imsave(
    459             filename_or_obj, self.buffer_rgba(), format=fmt, origin="upper",

/usr/local/lib/python3.10/dist-packages/matplotlib/backends/backend_agg.py in draw(self)
    398              (self.toolbar._wait_cursor_for_draw_cm() if self.toolbar
    399               else nullcontext()):
--> 400             self.figure.draw(self.renderer)
    401             # A GUI class may be need to update a window using this draw, so
    402             # don't forget to call the superclass.

/usr/local/lib/python3.10/dist-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     93     @wraps(draw)
     94     def draw_wrapper(artist, renderer, *args, **kwargs):
---> 95         result = draw(artist, renderer, *args, **kwargs)
     96         if renderer._rasterizing:
     97             renderer.stop_rasterizing()

/usr/local/lib/python3.10/dist-packages/matplotlib/artist.py in draw_wrapper(artist, renderer)
     70                 renderer.start_filter()
     71 
---> 72             return draw(artist, renderer)
     73         finally:
     74             if artist.get_agg_filter() is not None:

/usr/local/lib/python3.10/dist-packages/matplotlib/figure.py in draw(self, renderer)
   3138 
   3139             self.patch.draw(renderer)
-> 3140             mimage._draw_list_compositing_images(
   3141                 renderer, self, artists, self.suppressComposite)
   3142 

/usr/local/lib/python3.10/dist-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    129     if not_composite or not has_images:
    130         for a in artists:
--> 131             a.draw(renderer)
    132     else:
    133         # Composite any adjacent images together

/usr/local/lib/python3.10/dist-packages/matplotlib/artist.py in draw_wrapper(artist, renderer)
     70                 renderer.start_filter()
     71 
---> 72             return draw(artist, renderer)
     73         finally:
     74             if artist.get_agg_filter() is not None:

/usr/local/lib/python3.10/dist-packages/matplotlib/axes/_base.py in draw(self, renderer)
   3062             _draw_rasterized(self.figure, artists_rasterized, renderer)
   3063 
-> 3064         mimage._draw_list_compositing_images(
   3065             renderer, self, artists, self.figure.suppressComposite)
   3066 

/usr/local/lib/python3.10/dist-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    129     if not_composite or not has_images:
    130         for a in artists:
--> 131             a.draw(renderer)
    132     else:
    133         # Composite any adjacent images together

/usr/local/lib/python3.10/dist-packages/matplotlib/artist.py in draw_wrapper(artist, renderer)
     70                 renderer.start_filter()
     71 
---> 72             return draw(artist, renderer)
     73         finally:
     74             if artist.get_agg_filter() is not None:

/usr/local/lib/python3.10/dist-packages/matplotlib/collections.py in draw(self, renderer)
    970     def draw(self, renderer):
    971         self.set_sizes(self._sizes, self.figure.dpi)
--> 972         super().draw(renderer)
    973 
    974 

/usr/local/lib/python3.10/dist-packages/matplotlib/artist.py in draw_wrapper(artist, renderer)
     70                 renderer.start_filter()
     71 
---> 72             return draw(artist, renderer)
     73         finally:
     74             if artist.get_agg_filter() is not None:

/usr/local/lib/python3.10/dist-packages/matplotlib/collections.py in draw(self, renderer)
    403             gc.set_antialiased(self._antialiaseds[0])
    404             gc.set_url(self._urls[0])
--> 405             renderer.draw_markers(
    406                 gc, paths[0], combined_transform.frozen(),
    407                 mpath.Path(offsets), offset_trf, tuple(facecolors[0]))

TypeError: must be real number, not str

 

 

해결 방법은 매우 간단했다. 그저 숫자로 들어가야 할 것이 문자열로 들어갔기 때문.. name이 문제인 줄 알았는데 다른 부분이 문제였다. tsne_plot 함수의 4, 5번째 코들줄에 있는 linewidth를 지정할 때 문제가 발생했던 것이었다.

linewidth='1'이 아니라 linewidth=1을 해주어야 한다. 아니 캐글에는 왜 이렇게 되어있던거람? 스택오버플로우를 보면 이전 버전의 matplotlib에서는 문제가 되지 않았지만, 현재에는 오류가 발생하게 되는 포인트인 것 같다.

 

그래서 실행이 되는 코드는 아래와 같다.

def tsne_plot(x1, y1, name="graph.png"):
    tsne = TSNE(n_components=2, random_state=0)
    X_t = tsne.fit_transform(x1)

    plt.figure(figsize=(12, 8))
    plt.scatter(X_t[np.where(y1 == 0), 0], X_t[np.where(y1 == 0), 1], marker='o', color='g', linewidth=1, alpha=0.8, label='Non Fraud')
    plt.scatter(X_t[np.where(y1 == 1), 0], X_t[np.where(y1 == 1), 1], marker='o', color='r', linewidth=1, alpha=0.8, label='Fraud')

    plt.legend(loc='best');
    print(name)
    print(type(name))
    plt.savefig(name);
    plt.show();
    
tsne_plot(X, Y, "original.png")

 

참고: https://stackoverflow.com/questions/68090145/python-type-error-raised-during-savefig-in-matplotlib