The signal is defined as data values that are represented by the signal vector at specified points in time. Let’s create a signal plot in Matlab and then in Python.
MATLAB and Python are powerful programming languages for various purposes, including numerical and scientific analysis. Both of these languages can display the data graphically.
We will create a Continuous Time (CT) signal, often used in analog systems. Let’s say we have a CT signal, for a time interval (0–20). Here is a signal defined as a function of time . Let’s look at the code to understand it:
time=0:0.01:20;signal=2*time.*cos(time);# Now Plottingh1=figure;plot(time,signal,'color','r');xlabel('Time');ylabel('CT Signal');title('Signal Plot');grid;
Line 1–2: We declare our axes i.e., time and signal.
Line 6: We plot the data values using the plot()
function. An important thing to note here is that time
is independent variable and signal
is a dependent variable. We also specify the color of the plotted signal.
Line 9: We use the grid
function to display the grid line on the plot.
Let’s create a sinusoidal signal, which is an example of a continuous-time signal, to understand the concept better. For example, we have a CT signal, for a time interval (0-10). Here is a signal defined as a function of time .
% time interval valuest = 0:0.01:10;% the signal valuesx = sin(2*pi*t);% Plotting the signalh1=figure;plot(t, x, 'color', 'b')xlabel('Time')ylabel('CT signal')title('Sinusoidal Signal')grid;
Line 2: We declare x-axis ie., time.
Line 5: We declare y-axis ie., signal.
Line 9: We plot the data values using the plot()
function. We also specify the color of the plotted signal.
Let's try to plot the same signal in Python:
# Importing pyplot and numpy from matplotlibfrom matplotlib import pyplot as pltimport numpy as np# Setting the figure sizeplt.rcParams['figure.figsize'] = (10,6)# Defining variablesinterval=0.01time=np.arange(0,20,interval)signal=2*time*np.cos(time)# Plottingplt.plot(time,signal,color="red")plt.grid()plt.margins(x=0)plt.xlabel('Time')plt.ylabel('CT Signal')plt.title('Signal Plot');plt.show()
Line 2–3: Importing some important libraries required for data arrangement and plotting i.e., matplotlib
and numpy
.
Line 9–11: We define the variables i.e., time
and signal
.
Line 14: Plotting the graph by using plt.plot()
function.
Line 20: The function plt.show()
is used to display the plot.
Let’s create a sinusoidal signal, which is an example of a continuous-time signal, to understand the concept better. For example, we have a CT signal, for a time interval (0-10). Here is a signal defined as a function of time .
# Importing pyplot and numpy from matplotlibfrom matplotlib import pyplot as pltimport numpy as np# Setting the figure sizeplt.rcParams['figure.figsize'] = (10,6)# Defining variablesinterval=0.01time=np.arange(0,10,interval)signal=np.sin(2*np.pi*time)# Plottingplt.plot(time,signal,color="red")plt.grid()plt.margins(x=0)plt.xlabel('Time')plt.ylabel('CT Signal')plt.title('Signal Plot');plt.show()
Line 2–3: Importing some important libraries i.e., matplotlib
and numpy
.
Line 9–11: Defining axes i.e., time
and signal
.
Line 14: Plotting the graph by using plt.plot() function.
Line 20: The function plt.show()
is used to display the plot.
Free Resources