diff --git a/filter_design/frequency_sampling_method.ipynb b/filter_design/frequency_sampling_method.ipynb
index fe29b85..ffc549f 100644
--- a/filter_design/frequency_sampling_method.ipynb
+++ b/filter_design/frequency_sampling_method.ipynb
@@ -3713,14 +3713,14 @@
     "\n",
     "# plot impulse response\n",
     "plt.figure(figsize=(10, 3))\n",
-    "plt.stem(h, use_line_collection=True)\n",
+    "plt.stem(h )\n",
     "plt.title('Impulse response')\n",
     "plt.xlabel(r'$k$')\n",
     "plt.ylabel(r'$h[k]$')\n",
     "# plot transfer functions\n",
     "plt.figure(figsize=(10, 3))\n",
     "plt.plot(Om, np.abs(H), 'b-', label=r'designed $|H(e^{j \\Omega})|$')\n",
-    "plt.stem(Ommu, np.abs(Hd), 'g', label=r'desired $|H_d[\\mu]|$', use_line_collection=True)\n",
+    "plt.stem(Ommu, np.abs(Hd), 'g', label=r'desired $|H_d[\\mu]|$' )\n",
     "plt.plot([0, Omc, Omc], [1, 1, 0], 'r--')\n",
     "plt.title('Magnitude response of desired/designed filter')\n",
     "plt.xlabel(r'$\\Omega$')\n",
@@ -7096,7 +7096,7 @@
     "\n",
     "# plot impulse response\n",
     "plt.figure(figsize=(10, 3))\n",
-    "plt.stem(h, use_line_collection=True)\n",
+    "plt.stem(h )\n",
     "plt.title('Impulse response')\n",
     "plt.xlabel(r'$k$')\n",
     "plt.ylabel(r'$h[k]$')\n",
@@ -7104,7 +7104,7 @@
     "plt.figure(figsize=(10, 3))\n",
     "plt.plot(Om, np.abs(H), 'b-', label=r'designed $|H(e^{j \\Omega})|$')\n",
     "plt.stem(Ommu, np.abs(Hd), 'g',\n",
-    "         label=r'desired $|H_d[\\mu]|$', use_line_collection=True)\n",
+    "         label=r'desired $|H_d[\\mu]|$' )\n",
     "plt.plot([0, Omc, Omc], [1, 1, 0], 'r--')\n",
     "plt.title('Magnitude response of desired/designed filter')\n",
     "plt.xlabel(r'$\\Omega$')\n",
@@ -10578,7 +10578,7 @@
     "\n",
     "# plot impulse response\n",
     "plt.figure(figsize=(10, 3))\n",
-    "plt.stem(h, use_line_collection=True)\n",
+    "plt.stem(h )\n",
     "plt.title('Impulse response')\n",
     "plt.xlabel(r'$k$')\n",
     "plt.ylabel(r'$h[k]$')\n",
diff --git a/filter_design/window_method.ipynb b/filter_design/window_method.ipynb
index 643250c..d7056df 100644
--- a/filter_design/window_method.ipynb
+++ b/filter_design/window_method.ipynb
@@ -3565,7 +3565,7 @@
     "\n",
     "# plot impulse response\n",
     "plt.figure(figsize=(10, 3))\n",
-    "plt.stem(h, use_line_collection=True)\n",
+    "plt.stem(h )\n",
     "plt.title('Impulse response')\n",
     "plt.xlabel(r'$k$')\n",
     "plt.ylabel(r'$h[k]$')\n",
@@ -7721,7 +7721,7 @@
     "\n",
     "# plot impulse response\n",
     "plt.figure(figsize=(10, 3))\n",
-    "plt.stem(h1, use_line_collection=True)\n",
+    "plt.stem(h1 )\n",
     "plt.title('Impulse response (rectangular window)')\n",
     "plt.xlabel(r'$k$')\n",
     "plt.ylabel(r'$h[k]$')\n",
diff --git a/quantization/linear_uniform_quantization_error.ipynb b/quantization/linear_uniform_quantization_error.ipynb
index 3d41acc..6981845 100644
--- a/quantization/linear_uniform_quantization_error.ipynb
+++ b/quantization/linear_uniform_quantization_error.ipynb
@@ -3710,7 +3710,7 @@
     "    plt.figure(figsize=(10, 6))\n",
     "    ccf = ccf[N-K-1:N+K-1]\n",
     "    kappa = np.arange(-len(ccf)//2, len(ccf)//2)\n",
-    "    plt.stem(kappa, ccf, use_line_collection=True)\n",
+    "    plt.stem(kappa, ccf )\n",
     "    plt.title('Cross-correlation function between input signal and error')\n",
     "    plt.xlabel(r'$\\kappa$')\n",
     "    plt.ylabel(r'$\\varphi_{xe}[\\kappa]$')\n",
diff --git a/random_signals/independent.ipynb b/random_signals/independent.ipynb
index edbeed3..a7ca1d7 100644
--- a/random_signals/independent.ipynb
+++ b/random_signals/independent.ipynb
@@ -316,14 +316,14 @@
     "plt.figure(figsize=(10, 4))\n",
     "\n",
     "plt.subplot(121)\n",
-    "plt.stem(kappa, ccf1, use_line_collection=True)\n",
+    "plt.stem(kappa, ccf1 )\n",
     "plt.xlabel('$\\kappa$')\n",
     "plt.ylabel(r'$\\varphi_{xy}[\\kappa]$')\n",
     "plt.title('CCF by dot product')\n",
     "plt.grid()\n",
     "\n",
     "plt.subplot(122)\n",
-    "plt.stem(kappa, np.abs(ccf1-ccf2), use_line_collection=True)\n",
+    "plt.stem(kappa, np.abs(ccf1-ccf2) )\n",
     "plt.xlabel('$\\kappa$')\n",
     "plt.title('Difference (magnitude)')\n",
     "plt.tight_layout()"
diff --git a/random_signals/superposition.ipynb b/random_signals/superposition.ipynb
index 55f902e..456de7d 100644
--- a/random_signals/superposition.ipynb
+++ b/random_signals/superposition.ipynb
@@ -7548,14 +7548,14 @@
     "plt.figure(figsize=(10, 10))\n",
     "\n",
     "plt.subplot(311)\n",
-    "plt.stem(y, use_line_collection=True)\n",
+    "plt.stem(y )\n",
     "plt.title('Signal')\n",
     "plt.xlabel(r'$k$')\n",
     "plt.ylabel(r'$x[k]$')\n",
     "plt.axis([0, K, -3, 3])\n",
     "\n",
     "plt.subplot(312)\n",
-    "plt.stem(kappa, acf, use_line_collection=True)\n",
+    "plt.stem(kappa, acf )\n",
     "plt.title('ACF of superposition')\n",
     "plt.xlabel(r'$\\kappa$')\n",
     "plt.ylabel(r'$\\varphi_{yy}[\\kappa]$')\n",
@@ -7563,7 +7563,7 @@
     "plt.grid()\n",
     "\n",
     "plt.subplot(313)\n",
-    "plt.stem(kappa, ccf, use_line_collection=True)\n",
+    "plt.stem(kappa, ccf )\n",
     "plt.title('CCF between noise and superposition')\n",
     "plt.xlabel(r'$\\kappa$')\n",
     "plt.ylabel(r'$\\varphi_{ny}[\\kappa]$')\n",
@@ -10484,14 +10484,14 @@
     "plt.figure(figsize=(10, 10))\n",
     "\n",
     "plt.subplot(311)\n",
-    "plt.stem(y[0, :100], use_line_collection=True)\n",
+    "plt.stem(y[0, :100] )\n",
     "plt.title('One observation')\n",
     "plt.xlabel(r'$k$')\n",
     "plt.ylabel(r'$y_0[k]$')\n",
     "plt.ylim([-3, 3])\n",
     "\n",
     "plt.subplot(312)\n",
-    "plt.stem(xhat[Nmax-1, :100], use_line_collection=True)\n",
+    "plt.stem(xhat[Nmax-1, :100] )\n",
     "plt.title('Average over {:2.0f} observations'.format(Nmax))\n",
     "plt.xlabel(r'$k$')\n",
     "plt.ylabel(r'$\\hat{x}[k]$')\n",
diff --git a/random_signals/white_noise.ipynb b/random_signals/white_noise.ipynb
index bf08f0c..0cc593d 100644
--- a/random_signals/white_noise.ipynb
+++ b/random_signals/white_noise.ipynb
@@ -78,7 +78,7 @@
     "\n",
     "    # plot ACF\n",
     "    plt.subplot(122)\n",
-    "    plt.stem(kappa, acf, use_line_collection=True)\n",
+    "    plt.stem(kappa, acf )\n",
     "    plt.title('Estimated ACF')\n",
     "    plt.ylabel(r'$\\hat{\\varphi}_{nn}[\\kappa]$')\n",
     "    plt.xlabel(r'$\\kappa$')\n",
diff --git a/recursive_filters/direct_forms.ipynb b/recursive_filters/direct_forms.ipynb
index 857089e..1d3b8a6 100644
--- a/recursive_filters/direct_forms.ipynb
+++ b/recursive_filters/direct_forms.ipynb
@@ -1184,7 +1184,7 @@
     "\n",
     "# plot output signal\n",
     "plt.figure(figsize=(8, 4))\n",
-    "plt.stem(h, use_line_collection=True)\n",
+    "plt.stem(h )\n",
     "plt.title('Impulse response')\n",
     "plt.xlabel(r'$k$')\n",
     "plt.ylabel(r'$h[k]$')\n",
diff --git a/recursive_filters/introduction.ipynb b/recursive_filters/introduction.ipynb
index 9103a65..69394a1 100644
--- a/recursive_filters/introduction.ipynb
+++ b/recursive_filters/introduction.ipynb
@@ -4735,7 +4735,7 @@
     "plt.title('Phase response')\n",
     "# plot impulse response (magnitude)\n",
     "plt.figure(figsize=(10, 3))\n",
-    "plt.stem(20*np.log10(np.abs(np.squeeze(h))), use_line_collection=True)\n",
+    "plt.stem(20*np.log10(np.abs(np.squeeze(h))) )\n",
     "plt.xlabel(r'$k$')\n",
     "plt.ylabel(r'$|h[k]|$ in dB')\n",
     "plt.grid()\n",
diff --git a/recursive_filters/quantization_of_variables.ipynb b/recursive_filters/quantization_of_variables.ipynb
index 998ac14..1cb71bc 100644
--- a/recursive_filters/quantization_of_variables.ipynb
+++ b/recursive_filters/quantization_of_variables.ipynb
@@ -4951,7 +4951,7 @@
     "\n",
     "plt.figure(figsize=(10, 3))\n",
     "k = np.arange(1000, 1050)\n",
-    "plt.stem(k, yQ[k]/Q, use_line_collection=True)\n",
+    "plt.stem(k, yQ[k]/Q )\n",
     "plt.title('Output signal for zero input')\n",
     "plt.xlabel(r'$k$')\n",
     "plt.ylabel(r'$y_Q[k] / Q$ ')\n",
@@ -8448,7 +8448,7 @@
     "\n",
     "plt.figure(figsize=(10, 3))\n",
     "k = np.arange(1000, 1050)\n",
-    "plt.stem(k, yQ[k], use_line_collection=True)\n",
+    "plt.stem(k, yQ[k] )\n",
     "plt.title('Output signal for zero input')\n",
     "plt.xlabel(r'$k$')\n",
     "plt.ylabel(r'$y_Q[k]$ ')\n",
diff --git a/spectral_analysis_deterministic_signals/summary.ipynb b/spectral_analysis_deterministic_signals/summary.ipynb
index 73727e4..7935a56 100644
--- a/spectral_analysis_deterministic_signals/summary.ipynb
+++ b/spectral_analysis_deterministic_signals/summary.ipynb
@@ -1678,7 +1678,7 @@
     "    '''Plot magnitude spectrum.'''\n",
     "    plt.axvline(x=P, linewidth=2, color='C1', alpha=.5)\n",
     "    plt.stem(mu, 20*np.log10(np.abs(X)), basefmt=' ',\n",
-    "             bottom=-300, use_line_collection=True)\n",
+    "             bottom=-300 )\n",
     "    plt.title(title)\n",
     "    plt.xlabel(r'$\\mu$')\n",
     "    plt.axis([0, N, -100, 40])\n",
diff --git a/spectral_estimation_random_signals/welch_method.ipynb b/spectral_estimation_random_signals/welch_method.ipynb
index bf9ae5e..12e586e 100644
--- a/spectral_estimation_random_signals/welch_method.ipynb
+++ b/spectral_estimation_random_signals/welch_method.ipynb
@@ -1499,7 +1499,7 @@
     "# plot results\n",
     "plt.figure(figsize=(10, 4))\n",
     "plt.stem(Om, Pxx, 'C0',\n",
-    "         label=r'$\\hat{\\Phi}_{xx}(e^{j \\Omega})$', basefmt=' ', use_line_collection=True)\n",
+    "         label=r'$\\hat{\\Phi}_{xx}(e^{j \\Omega})$', basefmt=' ' )\n",
     "plt.plot(Om, np.ones_like(Pxx), 'C1', label=r'$\\Phi_{xx}(e^{j \\Omega})$')\n",
     "plt.title('Estimated and true PSD')\n",
     "plt.xlabel(r'$\\Omega$')\n",