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Best answer by LucMeekes

No, they should not.

 

You did not define the variable 'freq'. This means that you left it to Mathcad to pick a suitable range for frequencies when you created the 'autoplot' (which is a nice feature, but as all features: to be handled with care).

In the case of mathcad 11, it took a linear range, starting at 10 (maybe) and stepping to 10^9 with steps of 10^6. That is why there are no (additional) points in the range of freq between 10 and one million.

In the case of mathcad 15, it probably took a range of frequencies logarithmically spaced from 10 to 10^9 with maybe 20 points per decade.

If you add this,

LucMeekes_0-1624308908079.png

 

above the plot, tou your Mathcad 11 sheet, the you have defined freq as an array of frequencies, logarithmically spaced from 10  to 10^9 at 20 points per decade. And f is an index into that array.

Now all there is left to be done is to handle freq as an array in your plots, so add [f at the end each occurrence of freq in your plots.

Note that in mathcad 15 a function logspace() is available that can create a similar array.

 

Success!
Luc

 

 

1 reply

L
LucMeekes23-Emerald IVAnswer
23-Emerald IV
June 21, 2021

No, they should not.

 

You did not define the variable 'freq'. This means that you left it to Mathcad to pick a suitable range for frequencies when you created the 'autoplot' (which is a nice feature, but as all features: to be handled with care).

In the case of mathcad 11, it took a linear range, starting at 10 (maybe) and stepping to 10^9 with steps of 10^6. That is why there are no (additional) points in the range of freq between 10 and one million.

In the case of mathcad 15, it probably took a range of frequencies logarithmically spaced from 10 to 10^9 with maybe 20 points per decade.

If you add this,

LucMeekes_0-1624308908079.png

 

above the plot, tou your Mathcad 11 sheet, the you have defined freq as an array of frequencies, logarithmically spaced from 10  to 10^9 at 20 points per decade. And f is an index into that array.

Now all there is left to be done is to handle freq as an array in your plots, so add [f at the end each occurrence of freq in your plots.

Note that in mathcad 15 a function logspace() is available that can create a similar array.

 

Success!
Luc

 

 

    C
    Cornel19-TanzaniteAuthor
    19-Tanzanite
    June 22, 2021

    All the results below in the graphs are taken from Mathcad 11.

    --------------------------------
    With 

    CornelBejan_10-1624340370714.png


    Case 1:

    CornelBejan_0-1624339881510.png

     

     

    CornelBejan_1-1624339966104.png

     

    Case 2:

    CornelBejan_2-1624339995161.png

     

    CornelBejan_3-1624340044779.png

     

    Case 3:

    CornelBejan_4-1624340084642.png

     

    CornelBejan_5-1624340110549.png

     

    CornelBejan_6-1624340125337.png

     

    CornelBejan_16-1624340641799.png

     

    CornelBejan_17-1624340708553.png

     

    --------------------------------

    Without:

    CornelBejan_9-1624340327525.png

     

    Case 1:

     

    CornelBejan_11-1624340408426.png

     

     

    CornelBejan_12-1624340462027.png

    Case 2:

    CornelBejan_13-1624340483601.png

     

    CornelBejan_14-1624340534452.png

    Case 3:

    CornelBejan_15-1624340566511.png

     

    CornelBejan_5-1624340110549.png

     

    CornelBejan_6-1624340125337.png

     

    CornelBejan_16-1624340641799.png

     

    CornelBejan_17-1624340708553.png

    --------------------------------


    On the other hand, what I find a little strange is that in Mathcad 15 once I checked the box corresponding to the x-axis in which I specify to the graph that the x-axis represents a logarithmic axis then I don't have to create a variable for the x-axis so that I clearly specify that the x-axis is a logarithmic axis because I created a variable to do this, while, as you say, in Mathcad 11 I have to create such a variable even if I checked the x-axis box in which tell him that the x-axis represents a logarithmic axis.

    Therefore why in Mathcad 15 I do not have to create such a variable to take into account that the x-axis represents a logarithmic axis (it is enough only if I specify in the graph properties that the x-axis represents a logarithmic axis), and in Mathcad 11 do I have to create such a variable that takes into account the fact that the x-axis represents a logarithmic axis (even if in the properties of the graph I checked that the x-axis is a logarithmic axis)?

    And could you put a Mathcad 11 file with the implementation of the version you are talking about?
    It would be useful for me to have an example as an example 🙂

    (Attached is a Mathcad 11 File)

    Thanks.

     

    L
    LucMeekes23-Emerald IV
    23-Emerald IV
    June 22, 2021

    You forgot to put f as an index to freq every where you use freq in the plots.

     

    Success!
    Luc

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