LabVIEW Idea Exchange

In the series "Intended versus expected" (or blue versus orange), this is a discussion of a not very helpful feature of the Ramp Pattern VI:

If you ask for a single sample (samples = 1) from the Ramp Pattern AND do not set "exclude end?" to True, the VI returns an error -20006: "Analysis:  The number of samples must be >= 2."

The Help specifies that: " If samples is 1 and exclude end? is TRUE, the VI returns an array with one element of start."

It doesn't say anything about the situation I described previously, but most likely the error comes from the likely following definitions of the array {xi} of values (in the linear case):

1) exclude end? xi = xs + i*(xe-xs)/N, where i = 0,..., N-1 and (xs, xe) are the start and end points respectively

2) do not exclude end: xi = xs + i*(xe-xs)/(N-1).

In the second case, N = 1 results in a division by zero, hence an error.

So far so good, but here is the catch: Suppose I want to build a curve with equidistant abscissa (number N), comprised between a start and end points xs and xe (both included). It seems like the Ramp Pattern has been designed for me, right?

Wrong. If I set xs = xe and N = 1, I would expect a single point, equal to xs = xe. Instead, I get an error. So my first contention is that this should be a detected case: xe = xs AND N = 1, should result in a single element array equal to xe = xs.

Now, what I would suggest is that if xs != xe AND N = 1, then the Ramp Pattern could return a single element equal to (xs + xe)/2 (and a similar definition for a logarithmic ramp).

LabVIEW should ship with a Set Operations palette item, including the common operations such as Union, Intersection, Complement, and Cartesian Product, as well as more advanced operations that I don't know about. These operations would act on 1D arrays of almost anything. Floating point numbers and those would have to have some kind of "error in value" input that defaults to the machine epsilon or equality checking. Output would be a 1D array on the input datatype with the values, and perhaps an output for matched indices.

Yes, these are quite easy to make yourself (loop+search), but I think that it would be beneficial for the community for NI to provide it. The VIs found at http://zone.ni.com/devzone/cda/epd/p/id/3929  are... Interesting, to say the least. NI might be able to provide better performance, too.

I don't know much about the AVI format, so I am unsure if this is even possible.  But I would love to have the following additional functions in NI Vision's AVI aubVIs:

• Delete AVI frame
• Insert AVI frame

I need the IMAQ Correlate function

to work on a sub-pixel (super resolution) basis. For sub-pixel resolution capability, you will have to change the internal mathematics of this function for floating point calculations.

This function, as I am recommending for all of the Vision functions, should be made compatible with U16 image type as well.  (Currently, it is only compatible with U8 image type.)

Hello,                    (sorry for my english, i will try to do my best)

I think the management of Breakpoints and  Probes is not logical and not enough powerful.

I propose a new approach. 

LabVIEV would need a real debugging environment, much more powerful, like this :

1st  :  Probe management is not logical

           Why ?  A probe is only to watch a value on a wire (not to stop the code)

2nd : To stop the code, the Breakpoint, with ou without condition(s) ... (conditional or unconditional Breakpoint)

3rd  : Conditional Breakpoint:

•   A conditional Breakpoint stops the code on a wire, according condition(s) on this wire itself;

       or / and  according condition()s on other wires. (very powerful feature)

•  The breakpoint condition use binary operators (C language), like a Formula Node

•  To Use a Numeric value or a boolean value into a Condition, you must first place a Probe

      (Normal, before using a value, we must first take it.)

•   The Conditional Breakpoints are only available with Numeric and Boolean values.

      (As the current version of LV)

The breakpoint Manager highlights the Breakpoint on which the right click has been made.

Inside the Breakpoint Manager, we can see the corresponding Breakpoint via "Find on Diagram".

I've posted an idea, but didn't add any pic to explain:
http://forums.ni.com/t5/ideas/v2/ideapage/blog-id/labviewideas/article-id/16975/tab/rich

I've attached an image with this idea. Sorry for the duplicate posts.

These are simple examples but can get more complicated. For example, usage 2 can have more input (e.g. 4) it will have 16 possibilities which have different simplified code.

USAGE 1: User wires some input on the block diagram, when the simplify button is used, it simplifies the complicated code to a simple one ( noting that it is not the unique solution as shown in USAGE 3)

USAGE 2: If for the application, the user changes the value of the input and he gets different output; this table can get the simplified; or the "best fit" for the number of data present.

In http://forums.ni.com/t5/ideas/v2/ideapage/blog-id/labviewideas/article-id/16975/tab/rich, I wanted to compare that  Partial fraction expansion vi is not widely used except for certain applications yet it is important and beneficial.

Same goes for this idea.

Best