Solving functional equation and or evaluating non-linear equations

Does anyone know of a computer program that will do either or preferably both of the following:
1: a functional equation; e.g. 4x^2exp(-1/1-x^2) -6x = 0;
2: Evaluate a function at specified points; e.g. what is the value at -.5 of the above expression.
i imagine excels solver does the second but I didn't load solver when I loaded excel.
I'm not too proud to accept solutions as well. Many thanks.

Is it what you wanted ?
In cells of column B, the formula is :
=IFERROR(INDIRECT(ADDRESS(1,2,,,A&" "&$A$1)),"")
Between the late double quotes I insreted the character INFINITY ($221E)
Yvan KOENIG (VALLAURIS, France) mercredi 21 avril 2010 20:44:36

Similar Messages

Solving Coefficients for Non-Linear Equation

I have the following equation that I need to solve a, b and c. y = a+bexp(-x/c). Is there a VI that is written to help me?

i don't understand what do you suppose to mean?
you have not a,b and c values and you wanna solve 3 unknown variables with just one equation?
do you think is that possible?
even you had x and y values!
but if you have 4 values and you just want to find another variables value it's so easy
you can easily use a formula node.
i have write a simple program for you to solve this equation and i attached it to this answer.
it's with LabVIEW 5.
Attachments:
formula_node_example.vi ‏25 KB

Lens Distortion Non-linear Distortion and Perspective Distortion

Hello everyone, I'm a member of the vision team in the Intelligent Ground Vehicle team in Cal State Northridge, an autonomous robot that uses real time feed and laser data as sensors.
So we need a fully undistorted video feed for us to do image analysis with the lowest processing time.
We have a distortion situation with our current vision system where we have to fix Non-linear Distortion due to the use of a wide lens ( About 144 Deg ) and also Perspective Distortion of the projected image. The camera is mounted on top of our robot with an angle with the ground (about 45 Deg).
I have been using labview for about 6 months, and have been trying to correct this distortion using Vision Assistant program to generate VI's.
First I'll list my attempts here and then I will direct some questions.
First attempt, a picture of a dot grid was taken with our camera and that picture was correct by Vision Assistant's nonlinear image calibration. Then a VI was generated by Vision Assistant, and we changed in the input from images to video.
This method worked but not accurately.
Second attempt, we tried to remap the image pixels using a correction function generated through Excel, this method did not work accurately either. I'm not even sure how to do this again since it was done in the past.
So my questions are here:
1) what's the best approach to correct the distortion in our camera? and how please.
2) what are we doing wrong/right in general?
3) Generally, how would I improve any vision VI to reach faster processing times?
Everyone's help is very much appreciated,
Omar
Cal State Northridge
The Intelligent Ground Vehicle team
[email protected]

I'd like to correct the information provided by Bruce. It was correct up til Vision Development Module 2010. You need to update, Bruce ;-)
In Vision Development Module 2011, we improved the accuracy and precision of our grid calibration, by computing a lens distortion model (Division or Polynomial Model), that take into account radial and tangential non-linear distortion of the lens. The new algorithm also allows to compute the internal parameters of the lens (focal length and optical center), that you can use to determine the relationship of the camera to the object under inspection.
The microplane algorithm that Bruce described is still availale, as it can be used to solve applications in which the object you're trying to calibrate is non planar, and can be calibrated by wrapping the grid around the object.
A calibration will be valid for a specific perspective plane, and will need to be recomputed if the camera moves or object is in a different plane.
Typically, the calibration process is an offline process. For performance reasons, you don't necessarily want to correct the entire image (although VDM provides you with that function). As Bruce mentioned, most algorithms, like edge detection, pattern matching etc, return their data both in pixels and real-word data, talking into account the calibration information that you learned. For the few algorithms that only provide pixel results, you can use VIs to convert Pixels to Real-World. This operation is fast.
What type of features are you trying to measure in the image? Can it be solved in 2D, or do you need 3D information? How many cameras do you have on the robot?
-Christophe

Non-linear equation solution

I have used Lev-Mar Non-Linear VI before but cannot understand how to apply to the following:
deltaTC = R(TC)*L^2 + QS + QC(TC) +QR(TC)*dt
where variables containing (TC) are dependent on TC.
I have samples of change of L over time (dt). Trying to determine dTC with variables dependent on TC (current value - which means initial T + dTC).
Any help much appreciated.

Hi Battler,
I am not sure if you know this or not but Lev-Mar Non-Linear VI is not supported any more. Instead you can use Nonlinear Curve Fit.vi . It is located in function->mathematics->fitting palette.
The functionality of both of them is the same.Next you can go LabVIEW help, search for this VI, and then look at the "Linear, Exp, and Power Fitting VI: labview\examples\math\curvefit.llb"
example. On the block diagram go to "Time out"and "true" for the case structures.You will see the Nonlinear Curve fit.vi, you need to input your equation to the reference terminal f(x,a). So
you need to make a subVI of your equation, and input it into f(x,a). Hope this helps!!
Edna
National Instruments
Applications Engineer

Non linearity between pixels and widht for linescan

Hi
I'm developing a width gauge based on a linescan camera.
The gauge is measuring the surface of a steel strip moving at 200m/sec.
I found a non linearity between the relation of pixels and real widht:
1904mm X 6635,6pixels
1308mm X 4616,7pixels
814mm X 2880,6pixels
I've tried the working distances between 2600 to 2800mm.
The field of view is 2200mm.
The focal lengh is 35mm.
The size of CCD is 28.67mm (3.5um X 8192pixels - Basler raL8192-12gm).
Somebody already faced this problem?
Thanks,
Alexandre.
Solved!
Go to Solution.

Hi Greg
Thanks for your idea. I implemented a polynomial from Excel according the attached. It's running well until now.
Another problem that I'm facing is the oscilation on the image (https://www.dropbox.com/s/cboyglx74g8sd93/width%20gauge.mp4?dl=0) when the grid and filter are applied. I would like get stable the filtered image and grid from edge detector.
Does anyone know how to solve this?
Thanks for the moment.
Attachments:
calibrcurve_ml2.xlsx ‏20 KB

HT201401 I had restored my iPhone 4 but after restore my camera can't function well after take picture from the camera it's didn't display in the Photo Gallery even can't take a video record,how to solve this?and i had tried to restore again,still the sam

I had restored my iPhone 4 but after restore my camera can't function well after take picture from the camera it's didn't display in the Photo Gallery even can't take a video record,how to solve this?and i had tried to restore again,still the same
kindly reply and fix this for me
reply to my email,tq

Most likely you have Office 2004 which are PPC-only applications and will not work in Lion. Upgrade to Office 2011. Other alternatives are:
Apple's iWork suite (Pages, Numbers, and Keynote.)
Open Office (Office 2007-like suite compatible with OS X.)
NeoOffice (similar to Open Office.)
LibreOffice (a new direction for the Open Office suite.)

Question about DBMS_PREDICTIVE_ANALYTICS and non-linear data

Hi,
I am executing DBMS_PREDICTIVE_ANALYTICS against some data, but it's not giving me good predictions for my null data. Should I be using different data mining techniques ?
The data has the following fields 1) Position, 2) Odds, 3) Selection & 4) Event.
Position and Odds and linear, since the smaller the number the higher the likelihood of winning, but Selection is a lookup based on a Name, so therefore non-linear, but can be used to look at previous form in the same data set. Event is a way to group Selection's into an Event.
What's the best way to tackle this ?

Sorry for delay, been on vacation.
I'm trying to improve odds for predicting winners, given the form, odds, previous history, and form of other runners in the race.
Take a look at data.betfair.com for a list of data elements available to me.
I'm currently using the data where the latest_taken column has the highest value. i.e. the odds and ranking just before the race starts.

Universe.applyOverload Method Run non-linearly slower and slower

Universe.applyOverload Method Run non-linearly slower and slower, that is, for the 10th user and restriction we add, this method runs 1 second, however, for the 80th user and restriction we add, this method runs 8 seconds.
Customers think it's a bug for our BOE Java SDK method, could I know why this method is non-linear, and any way to improve its running speed.
The following is the code, for interator 80 times.
while (iter.hasNext())
                    user = (rpt_users_t) iter.next();
                    IOverload overload = (IOverload) newObjs.add("Overload");
                    overload.setTitle(user.getBoezh().trim());
                    overload.setUniverse(universe.getID());
                    overload.setConnection(connectionID);
                    overload.getRestrictedRows().clear();
                    overload.getRestrictedRows().add("HZB0101_T","HZB0101_T.BRANCH_COMPANY_CODE='3090100' AND HZB0101_T.DEPARTMENT_CODE='"+ user.getBmdm() + "'");
                    overload.getRestrictedRows().add("BM_T","BM_T.DEPARTMENT_GROUP_CODE='" + user.getBmzdm().trim()+ "'");
                    infoStore.commit(newObjs);
                    // Commit to User
                    IInfoObject everyone = (IInfoObject) infoStore.query(
                              "Select TOP 1 SI_ID " + " From CI_SYSTEMOBJECTS "+ " Where SI_KIND='User' " + " And SI_NAME='"+ user.getBoezh().trim() + "'").get(0);
                    int everyoneID = everyone.getID();
                    universe.applyOverload(overload, everyoneID, true);
                    //infoStore.commit(objs);
                    System.out.println(user.getBoezh() + " loading...");

When invoking applyOverload multiple times, it's O(N^2) if you're granting rights to a User or UserGroup.
When granting, the applyOverload method retrieves all Overloads applied to the Universe and walks across each one, granting the identified ones and removing rights from others.
Sincerely,
Ted Ueda

AppStore displays permanently an update avaible and there is none really, how can I solve these little problem?

AppStore displays permanently an update avaible and there is none really, how can I solve these little problem?

Try:
- Reset the iOS device. Nothing will be lost
Reset iOS device: Hold down the On/Off button and the Home button at the same time for at
least ten seconds, until the Apple logo appears.
- Sync with iTunes
- Reset all settings
Go to Settings > General > Reset and tap Reset All Settings.
All your preferences and settings are reset. Information (such as contacts and calendars) and media (such as songs and videos) aren’t affected.
- Restore from backup. See:
iOS: How to back up
I myself would live with it before doing the following
- Restore to factory settings/new iOS device.

Hi I'm new to Mac. I have a macbook air and for some reason the top keys, ec, f1 etc etc are not functioning and emitt the non function noise when pressed. Also the volume keys don't adjust the volume. Have I done something to disable them?

Hi I'm new to Mac. I have a macbook air and for some reason the top keys, ec, f1 etc etc are not functioning and emitt the non function noise when pressed. Also the volume keys don't adjust the volume. Have I done something to disable them?

I don't have the same version of OS X here but try System Preferences>Keyboard. Is there an option similar to "Use the F1, etc, keys as standard function keys"?
If so, and it has a checkmark, uncheck it & see if that does the trick.
~Lyssa

Semiconductor strain and non linear scales

Dear,
it's not completely clear to me if it's possible to read semiconductor strain gauges with NI hardware?
Do I need special hardware or do I use a normal bridge circuit analog input card (eg NI 9237)?
An added problem with semiconductor strain gauges is the need for linearization of the output because the
basic resistance versus strain characteristic is nonlinear. Is this possible in LabView?
As far as I know, I can only create linear scales in Ni Max?
Thanks in advance,
Ronny Comyn
Belgium

Yes you can read strain gauges.
No, you dont need special hardware, but it makes things alot easier as signal levels are already adapted.
There's a Convert Strain Gauge Reading which you can read the help text about, depending on the bridge type it'll use different (some are non linear) conversions.
/Y
LabVIEW 8.2 - 2014
"Only dead fish swim downstream" - "My life for Kudos!" - "Dumb people repeat old mistakes - smart ones create new ones."
G# - Free award winning reference based OOP for LV

Non-linear ODE

Hello everybody,
Does anybody know if non-linear second order ODE can be solved with the Runge-Kutta solver. This appears to be the most common solver.
I am trying to solve a non-linear second order differential equation of the form x*x’’ +x’^2 =Const. I was looking for an example that I could use to start with and follow it. I found one called “SHOOTING METHOD”.
for f(x(t),y(t),y) I used (1/x)*(-y*y+Const)
Originally, I used x(0) =0.01 and x(1) = 0.01 for my boundary conditions but the solution just increases linearly with time as opposed to reaching a maximum and decreasing back to zero in time.
Any help is greatly appreciated. Thanks in advance.
Roberto

A shooting method reformulates the BVP as an optimization of the initial conditions of IVP. In your 2nd order ODE that means that the initial conditions are y(0) and y'(0), and the specified boundary conditions are y(0) and y(1). The first initial condition is just the first boundary condition, but y'(0) must be determined to produce y(1). I wrote a VI that sweeps over a series of y'(0) values, solves the ODE for each set of initial conditions, and graphs y(1)-desired_boundary. If y(1)-desired_boundary=0 then the initial conditions exactly produces the desired boundary conditions. Please see 'sweep rhs1.vi' in the attached archive. Run using the defaults. Once the zero is bracketed then an automatic root finder may be employed to solve for the initial condition with more precision. The zero-finder must have a bracketed interval (change in sign of the function around the desired level). See optimize rhs1.vi for an example using a Newton-Raphson zero finder to solve for the y'(0)initial condition.
Please note that the Newton-Raphson is a 1-D implementation only.
-Jim
Attachments:
shooting method.zip ‏43 KB

Is it possible to simulate large-scale non-linear systems using the Simulation Toolkit?

Hi,
I am new to LabVIEW, having used Matlab/simulink for a few years. I am trying to simulate a relatively complex non-linear vehicle model. In Matlab/Simulink I would use an m-file to describe the system equations (i.e. x1_dot=..., x2_dot=..., etc.). Is there a similar method in LabVIEW? I have got a simple simulation running using the 'eval formula node', a very ungainly method of substituting variables, and an integrator in a 'simulation node'. It takes about an hour to run a simulation that takes 3 seconds in Matlab. I just need to know if it is realistic to do large-scale simulations in LabVIEW, or if it was not designed for that and I should persuede the management to go
back to Matlab!!!
If it is possible, where can I find help on the subject? I have spent a long time looking on the web and come up with very little.
Many thanks in advance,
Paul.

If these are simple differential equations, easiest would be a for loop with a bunch of shift registers, one for each x1, x2, etc. containing the current values.
In your case, you would calculate all the derivatives from the instantaneous values inside the loop, then add them to each value before feeding them to their respective shift register again.
The attached very simple example shows how to generate an exponential decay function using the formula dx/dt= kx (and k is negative). The shift register in initialized with the starting condition x=1.
LabVIEW Champion . Do more with less code and in less time .
Attachments:
DiffEQ.vi ‏33 KB

[SOLVED] Function Keys Problem On Dell Inspiron N5010

Yesterday I bought a new laptop (Dell Inspiron N5010) and immediately installed Arch Linux on it. But when I launched the installation framework, I needed to use fdisk to partition my drive manually and to open another tty, ctrl + alt + f2 or up to f7, none of them worked. When I use f4 or f5 for example, it changes the brightness of the screen cause these keys have icons on them which represent the brightness control. So I quitted, took care of that fdisk issue and got back, installed Arch Linux successfully. When launched in GNOME 3, nothing was changed. It still uses f1, f2, ... and so on as "just function keys" without using "Fn" key. It's fine somehow cause my system automatically detected those keys, I can use every single function of my keyboard. But without using Fn key, I can't actually use any fx key for my own use. For example, I can't use Tilda anymore cause when I use only f1, it tries to open monitor control stuff.
So... any ideas?
Edit: It seems that this problem is all about Arch Linux. A friend of mine has the same laptop and he has just tried Mint Debian RC and function keys worked properly. So, there's a problem and it seems it's related to Arch Linux (or maybe Xorg version, somehow?).
Last edited by Jeaquares (2011-05-18 13:07:06)

xdunlapx wrote:The function key on my dell laptop was set to the F keys, meaning you have to hit the function key and then an F key to activate the F key. I switched it in the bios so I don't have to hit the function key to activate the F keys. So I would have had to hit Fn+Ctrl-Alt-F1 for example to get to TTY 1. Now since i switched it off in the bios All I have to do is hit Ctrl-Alt-F1 to get to the terminal. But in order to turn off wifi from the F key (for example) I have to hit Fn+F2. It's switched.
I can't tell you how this was helpful. I've never noticed that there was an option in BIOS's Advanced menu for this. I updated it as "Function Key" and it solved my problem, thanks.

PL-SQL Solve: Using INSTR and SUBSTR

I am trying to work on this and cannot get a solution. Please help
You have to use INSTR and SUBSTR to solve
Question:
You have the following acceptable value
Numberic: 0-34
80-100
or Non Numberic X S U D- D D+
Im have to use INSTR and SUBSTR functions to test that the value is a valid (as above) number before TO_NUMBER is called:
SELECT TO_NUMBER('?? ') //HERE ?? and a space (for 100 etc) is for the values as above
FROM DUAL
WHERE ....INSTR(......)<=;
(Hence if the number is true then number comes back or it says no rows)
and also id non numberic it should also be tested.
I am completely unsure about it but tried this
SELECT TO_NUMBER('34 ')
FROM DUAL
WHERE INSTR('0123456789',1,1)<=9 (looking at first number ?)
AND
INSTR('0123456789',2,2)<=9
AND
INSTR('0123456789',3,3)=0;
Please help

We have the following value that we can use:
Numeric: 0-34 and 80-100 only
or Non Numberic X S U D- D D+
Have to use INSTR and SUBSTR functions to test that the value is a valid
(for now only trying to create a function which can later be put into a procedure.)
SELECT TO_NUMBER('12 ') //e.g HERE 12 and a space for the values as above
FROM DUAL
the where clause looks at all three spaces to make sure values are correct (given number or non-numberic values only)
(Hence if the number is true then number comes back (meaning true)
or it says NO rows)
If value is non numeric, test it to allow non numberic also.
I am completely unsure about it but tried this
SELECT TO_NUMBER('34 ')
FROM DUAL
WHERE INSTR('0123456789',1,1)<=9 (looking at first number ?)
AND
INSTR('0123456789',2,2)<=9
AND
INSTR('0123456789',3,3)=0;
Something like this has to be done.....subst (instr, x,x,) i think mite help.

Solving functional equation and or evaluating non-linear equations

Similar Messages

Maybe you are looking for