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本文通过对多个循环任务进行测试,比较了 Matlab 与 Python 的性能表现。通过实验分析发现,两种语言的执行时间随着循环次数增加呈线性增长趋势。以下是具体测试结果:
Matlab 代码:
N = 20:25;iters = 2.^N;time = zeros(1, length(N));a = 0.111;b = 0.222;for k = 1:length(N) t1 = clock; for i = 1:2^N(k) r = 0.5*a + 0.6*b; end t2 = clock; time(k) = etime(t2, t1);endplot(iters, time);xlabel('iter'); ylabel('time/s)'); Python 代码:
N = range(20, 26)iters = [2**n for n in N]ts = []a, b = 0.111, 0.222for n in N: t1 = time.time() for i in range(2**n): r = 0.5*a + 0.6*b t2 = time.time() ts.append(t2 - t1)_, ax = plt.subplots()ax.plot(iters, ts)ax.set_xlabel('iter'); ax.set_ylabel('time/s)') 结果对比:通过对比两种语言的执行时间,发现随着循环次数增加,两者时间增长均呈线性关系。然而,Python 的执行速度较慢,约为 Matlab 的 60 倍。
Matlab 代码:
N = 20:25;iters = 2.^N;time = zeros(1, length(N));a = 0.111;b = 0.222;M = [0.111, 0.222; 0.111, 0.222];for k = 1:length(N) t1 = clock; for i = 1:2^N(k) r = M(1,1)*a + M(1,2)*b; end t2 = clock; time(k) = etime(t2, t1);endplot(iters, time);xlabel('iter'); ylabel('time/s)'); Python 代码:
N = range(20, 26)iters = [2**n for n in N]ts = []M = np.array([[0.111, 0.222], [0.111, 0.222]])a, b = 0.111, 0.222for n in N: t1 = time.time() for i in range(2**n): r = M[0,0]*a + M[0,1]*b t2 = time.time() ts.append(t2 - t1)_, ax = plt.subplots()ax.plot(iters, ts)ax.set_xlabel('iter'); ax.set_ylabel('time/s)') 结果对比:测试结果表明,随着循环次数增加,两者时间增长仍然呈线性关系。然而,Python 的执行速度较慢,约为 Matlab 的 110 倍。将此结果与测试1进行对比,可以推测仅在 2x2 矩阵中索引一个数时,Python 的执行速度可能比 Matlab 慢 50 倍左右。
Matlab 代码:
N = 20:25;iters = 2.^N;time = zeros(1, length(N));a = 0.111;b = 0.222;M = [0.111, 0.222; 0.111, 0.222];for k = 1:length(N) t1 = clock; for i = 1:2^N(k) r = M(1,1); end t2 = clock; time(k) = etime(t2, t1);endplot(iters, time);xlabel('iter'); ylabel('time/s)'); Python 代码:
N = range(20, 26)iters = [2**n for n in N]ts = []M = np.array([[0.111, 0.222], [0.111, 0.222]])a, b = 0.111, 0.222for n in N: t1 = time.time() for i in range(2**n): r = M[0,0] t2 = time.time() ts.append(t2 - t1)_, ax = plt.subplots()ax.plot(iters, ts)ax.set_xlabel('iter'); ax.set_ylabel('time/s)') 结果对比:实验结果与预期一致,Python 的执行速度确实比 Matlab 慢 50 倍左右。这表明,Matrix 索引操作中的性能差异与之前测试中的加法操作相比,差异度大幅缩小。
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