在python librosa中創建圖形ctxt對象時出錯

Question

我正在嘗試使用librosa繪制一些.wav數據，但遇到一些異常問題，在谷歌搜索“創建圖形ctxt對象的python librosa錯誤”中找不到很多問題

def plot_waves(sound_names, raw_sounds):
    i = 1
    fig = plt.figure(figsize=(25, 60), dpi=900)
    for n, f in zip(sound_names, raw_sounds):
        print "plot_waves:", i
        plt.subplot(10, 1, i)
        librosa.display.waveplot(np.array(f), sr=22050)
        plt.title(n.title())
        i += 1
    print "plot_waves_loop_end"


    plt.suptitle("Figure 1: Waveplot", x=0.5, y=0.915, fontsize=18)

    #THIS LINE CAUSES THE ERROR
    plt.show()

可能與macOS有關。

我已經在virtualenv和外部嘗試過，兩種情況都存在相同的錯誤。

pip install {matplotlib，librosa，numpy}在virtualenv和外部都顯示為不需要更新

錯誤消息（超出此范圍並鎖定python-必須強制退出）

2017-03-24 22:15:03.393 python[62870:25289530] _initWithWindowNumber: error creating graphics ctxt object for ctxt:0x3653b, window:0x9754
2017-03-24 22:15:03.393 python[62870:25289530] _initWithWindowNumber: error creating graphics ctxt object for ctxt:0x3653b, window:0x9754
Mar 24 22:15:03  python[62870] <Error>: CGContextSetFillColorWithColor: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
Mar 24 22:15:03  python[62870] <Error>: CGContextSetStrokeColorWithColor: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
Mar 24 22:15:03  python[62870] <Error>: CGContextGetCompositeOperation: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
Mar 24 22:15:03  python[62870] <Error>: CGContextSetCompositeOperation: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
Mar 24 22:15:03  python[62870] <Error>: CGContextFillRects: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
Mar 24 22:15:03  python[62870] <Error>: CGContextSetCompositeOperation: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
Mar 24 22:15:03  python[62870] <Error>: CGContextGetCTM: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
Mar 24 22:15:03  python[62870] <Error>: CGContextGetDefaultUserSpaceToDeviceSpaceTransform: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
Mar 24 22:15:03  python[62870] <Error>: CGContextSaveGState: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
Mar 24 22:15:03  python[62870] <Error>: CGContextConcatCTM: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
Mar 24 22:15:03  python[62870] <Error>: CGContextSetCompositeOperation: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
Mar 24 22:15:03  python[62870] <Error>: CGContextSaveGState: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
Mar 24 22:15:03  python[62870] <Error>: CGContextSetCompositeOperation: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.

Answer 1

我認為問題不是dpi設置太高（900可能太過分了！），而不是刪除行（根據您的評論）。 嘗試將其減少（例如減少到30），它應該可以工作。

def plot_waves(sound_names, raw_sounds):
    i = 1
    fig = plt.figure(figsize=(25, 60), dpi=30)  ## changed from 900 to 30
    for n, f in zip(sound_names, raw_sounds):
        print "plot_waves:", i
        plt.subplot(10, 1, i)
        librosa.display.waveplot(np.array(f), sr=22050)
        plt.title(n.title())
        i += 1
    print "plot_waves_loop_end"


    plt.suptitle("Figure 1: Waveplot", x=0.5, y=0.915, fontsize=18)

    plt.show()