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Time dependent changes- | Time dependent changes- | ||
| − | 1. Time delay- | + | 1. Time delay- <br /> |
| + | |||
In simple terms you are shifting the original signal by a factor. | In simple terms you are shifting the original signal by a factor. | ||
For eg. | For eg. | ||
| Line 7: | Line 8: | ||
In this example as you can see, a simple way of understanding time shift/delay is by looking at how the graph changes when you want a shift in the signal. | In this example as you can see, a simple way of understanding time shift/delay is by looking at how the graph changes when you want a shift in the signal. | ||
| − | 2. Time scaling- | + | 2. Time scaling- <br /> |
| + | |||
[[File:Graph1.2.PNG|amplitude scaling graph example]] | [[File:Graph1.2.PNG|amplitude scaling graph example]] | ||
In simple terms you are shifting the height/width of the graph of a signal. The change in graph depends on the value of a. If |a|>0, then the height increases, else it decreases. | In simple terms you are shifting the height/width of the graph of a signal. The change in graph depends on the value of a. If |a|>0, then the height increases, else it decreases. | ||
| − | 3. Time reversal- | + | 3. Time reversal-<br /> |
| + | |||
[[File:Graph1.3.PNG|time reversal]] | [[File:Graph1.3.PNG|time reversal]] | ||
When you negate the independent variable, the graph of the dependent variable changes to a mirror image of the original graph. | When you negate the independent variable, the graph of the dependent variable changes to a mirror image of the original graph. | ||
| − | Even/Odd Signals- | + | Even/Odd Signals-<br /> |
| + | |||
[[File:Graph1.4.PNG]] | [[File:Graph1.4.PNG]] | ||
As can be seen in the above function, the graphs do not change when you substitute x as -x. Similarly in signals, when a signal remains unchanged under time negation, it is termed as an "even" signal. | As can be seen in the above function, the graphs do not change when you substitute x as -x. Similarly in signals, when a signal remains unchanged under time negation, it is termed as an "even" signal. | ||
Revision as of 20:15, 1 December 2018
Time dependent changes-
1. Time delay-
In simple terms you are shifting the original signal by a factor. For eg.
In this example as you can see, a simple way of understanding time shift/delay is by looking at how the graph changes when you want a shift in the signal.
2. Time scaling-
In simple terms you are shifting the height/width of the graph of a signal. The change in graph depends on the value of a. If |a|>0, then the height increases, else it decreases.
3. Time reversal-
When you negate the independent variable, the graph of the dependent variable changes to a mirror image of the original graph.
Even/Odd Signals-
As can be seen in the above function, the graphs do not change when you substitute x as -x. Similarly in signals, when a signal remains unchanged under time negation, it is termed as an "even" signal.
