exponential function

[gareth123]

I'm a beginner and only started using LabView a few days back.

I would like to learn the basic functions, however i do not have a guide.

As a start, can I know what diagrams I need to input to create an exponential function, and reflect the waveforms?

[gareth123]

I'm a beginner and only started using LabView a few days back.

I would like to learn the basic functions, however i do not have a guide.

As a start, can I know what diagrams I need to input to create an exponential function, and reflect the waveforms?

[Yair]

Go through these.

[Yair]

Go through these.

[gareth123]

this is something which i had tried, however i don't see any output waveforms.

did i miss out on something?

[jcarmody]

QUOTE (gareth123 @ Jan 18 2009, 01:37 AM)

this is something which i had tried, however i don't see any output waveforms.

did i miss out on something?

• You didn't wire anything into the graph
  
• Your formula only makes one data point; I think you need a chart instead
  
• Your formula calculates to a constant
  

Try this one

[gareth123]

QUOTE (jcarmody @ Jan 18 2009, 01:12 PM)

• You didn't wire anything into the graph
  
• Your formula only makes one data point; I think you need a chart instead
  
• Your formula calculates to a constant
  

Try this one

Thanks a lot. It sure helps. i tried to wire the exponential function into the graph but it seems it become loose ends.

To use a formula, can I say that I had to specify an input into the formula, and let the formula operate from there?

Another thing which I'm pretty curious about. At first, my formula was sin(2*pi) and why did you change it to sin(2*pi*mod(i,pi)) instead? what does the "mod(i,pi)" do?

[jcarmody]

QUOTE (gareth123 @ Jan 21 2009, 10:27 PM)

To use a formula, can I say that I had to specify an input into the formula, and let the formula operate from there?

You don't need to specify an input to a formula, but it's essentially a constant if there are no dependent variables.

QUOTE

Another thing which I'm pretty curious about. At first, my formula was sin(2*pi) and why did you change it to sin(2*pi*mod(i,pi)) instead? what does the "mod(i,pi)" do?

sin(2*pi) = 0, e^0 = 1. Your VI calculated to 1 every time the loop ran; I added to it to make it more interesting. http://zone.ni.com/reference/en-XX/help/371361A-01/lvtextmath/msfunc_mod/' target="_blank">mod is the modulo operator, mod(i,pi) gives you the remainder of i/pi.

[gareth123]

ok. this is something which i had tried earlier. I'm supposed to do a fourier transform of this signal.... exp(-alpha*t) where alpha is greater or less than 0.. the upper limit is inf and lower limit is 0. the waveform i got is a straight line, and there's this error -20003 i.e number of samples > 0.

I thought I had already defined the number of samples? Is that anything which I had missed out? Please see attached.

[gareth123]

QUOTE (gareth123 @ Jan 23 2009, 08:12 AM)

ok. this is something which i had tried earlier. I'm supposed to do a fourier transform of this signal.... exp(-alpha*t) where alpha is greater or less than 0.. the upper limit is inf and lower limit is 0. the waveform i got is a straight line, and there's this error -20003 i.e number of samples > 0.

I thought I had already defined the number of samples? Is that anything which I had missed out? Please see attached.

updated .vi file. I had changed the -inf icon to a numeric constant and it works. Now I would like to display the waveform in real time domain exponential signal, magnitude spectrum and phase spectrum.