Use of interp2 in an arbitrary dataset (2024)

11 Ansichten (letzte 30 Tage)

Ältere Kommentare anzeigen

Stathis Tingas am 27 Jan. 2024

  • Verknüpfen

    Direkter Link zu dieser Frage

    https://de.mathworks.com/matlabcentral/answers/2075161-use-of-interp2-in-an-arbitrary-dataset

  • Verknüpfen

    Direkter Link zu dieser Frage

    https://de.mathworks.com/matlabcentral/answers/2075161-use-of-interp2-in-an-arbitrary-dataset

Bearbeitet: Stathis Tingas am 28 Jan. 2024

In MATLAB Online öffnen

Hello,

I would appreciate any help on the following issue.

I have a small dataset (3x3 matrix) which descirbes a mechanical property (say Z) in 2d space. Each line describes the mechanical property in the 2d space, hence I basically have 3 values of Z in the 2d space. Column 1 has the x-coordinate, column 2 has the y-coordinate and column 3 the respective value for Z.

For the sake of an example, my data looks like this:

X Y Z

0.25 0.25 0.5

0.50 0.60 1.5

0.75 0.35 3.0

I want to interpolate (between the given values) and extrapolate (from 0 up to 1 for both X and Y), ideally using spline, cubic or makima.

My plan was to use the following code:

x=[0.25;0.50;0.75];

y=[0.25;0.60;0.35];

[X,Y] = meshgrid(x,y);

Z = [0.5; 1.5; 3.0];

[Xq,Yq] = meshgrid(0:.01:1, 0:.01:1);

Zq = interp2(X,Y,Z,Xq,Yq,'spline');

However, when I try that, I get the following error:

Error using griddedInterpolant

Interpolation requires at least two sample points for each grid dimension.

Error in interp2>makegriddedinterp (line 226)

F = griddedInterpolant(varargin{:});

Error in interp2 (line 134)

F = makegriddedinterp(X, Y, V, method,extrap);

Could anyone advise?

Thanks

0 Kommentare

-2 ältere Kommentare anzeigen-2 ältere Kommentare ausblenden

Melden Sie sich an, um zu kommentieren.

Melden Sie sich an, um diese Frage zu beantworten.

Antworten (2)

Walter Roberson am 27 Jan. 2024

  • Verknüpfen

    Direkter Link zu dieser Antwort

    https://de.mathworks.com/matlabcentral/answers/2075161-use-of-interp2-in-an-arbitrary-dataset#answer_1398476

  • Verknüpfen

    Direkter Link zu dieser Antwort

    https://de.mathworks.com/matlabcentral/answers/2075161-use-of-interp2-in-an-arbitrary-dataset#answer_1398476

In MATLAB Online öffnen

x=[0.25;0.50;0.75];

y=[0.25;0.60;0.35];

Z = [0.5; 1.5; 3.0];

[Xq,Yq] = meshgrid(0:.01:1, 0:.01:1);

F = scatteredInterpolant(x, y, Z);

Zq = F(Xq, Yq);

surf(Xq, Yq, Zq)

Use of interp2 in an arbitrary dataset (3)

4 Kommentare

2 ältere Kommentare anzeigen2 ältere Kommentare ausblenden

Stathis Tingas am 27 Jan. 2024

Direkter Link zu diesem Kommentar

https://de.mathworks.com/matlabcentral/answers/2075161-use-of-interp2-in-an-arbitrary-dataset#comment_3044546

  • Verknüpfen

    Direkter Link zu diesem Kommentar

    https://de.mathworks.com/matlabcentral/answers/2075161-use-of-interp2-in-an-arbitrary-dataset#comment_3044546

Bearbeitet: Stathis Tingas am 28 Jan. 2024

Dear @Walter Roberson

Thank you for your response but to my understanding, scatteredInterpolant does not allow the use of spline, cubic or makima functions? Am I right? If so, is there a workaround to use particularly spline or makima?

Thanks

Stathis

William Rose am 27 Jan. 2024

Direkter Link zu diesem Kommentar

https://de.mathworks.com/matlabcentral/answers/2075161-use-of-interp2-in-an-arbitrary-dataset#comment_3044566

  • Verknüpfen

    Direkter Link zu diesem Kommentar

    https://de.mathworks.com/matlabcentral/answers/2075161-use-of-interp2-in-an-arbitrary-dataset#comment_3044566

@Stathis Tingas,

You have 3 data points, on a 2D surface. That is the minimum number needed to define a plane (assuming they are not collinear). With so few points, you cannot estimate a more sophisticated surface, such as a spline. You would need at least 4 points (2 in each dimension) to use makima and at least 16 (4 in each dimension) to use spline. With only three points, linear interpolation is your only option.

Stathis Tingas am 27 Jan. 2024

Direkter Link zu diesem Kommentar

https://de.mathworks.com/matlabcentral/answers/2075161-use-of-interp2-in-an-arbitrary-dataset#comment_3044571

  • Verknüpfen

    Direkter Link zu diesem Kommentar

    https://de.mathworks.com/matlabcentral/answers/2075161-use-of-interp2-in-an-arbitrary-dataset#comment_3044571

Bearbeitet: Stathis Tingas am 28 Jan. 2024

Thank you @William Rose for your response. I wasnt actually aware of this requirement for spline and makima.

My dataset will generally be small but it will vary from 3 up to 11-12 points. You are saying that makima would need 4 points. Therefore, if the original dataset as an example has the following 4 points, how could I use makima or cubic?

x=[0.25;0.50;0.75;0.9];

y=[0.25;0.60;0.35; 0.7];

Z = [0.5; 1.5; 3.0; 3.5];

Thanks

Torsten am 27 Jan. 2024

Direkter Link zu diesem Kommentar

https://de.mathworks.com/matlabcentral/answers/2075161-use-of-interp2-in-an-arbitrary-dataset#comment_3044586

  • Verknüpfen

    Direkter Link zu diesem Kommentar

    https://de.mathworks.com/matlabcentral/answers/2075161-use-of-interp2-in-an-arbitrary-dataset#comment_3044586

Bearbeitet: Torsten am 27 Jan. 2024

In MATLAB Online öffnen

If your data are not gridded, you will have to live with "ScatteredInterpolant" and its interpolation methods.

And your four points in 2d constitute a curve. So Z could be interpolated on this curve maybe, but it makes little sense to treat them as sufficient to interpolate on a real two-dimensional rectangle.

x=[0.25;0.50;0.75;0.9];

y=[0.25;0.60;0.35; 0.7];

Z = [0.5; 1.5; 3.0; 3.5];

plot3(x,y,Z)

grid on

Use of interp2 in an arbitrary dataset (8)

Melden Sie sich an, um zu kommentieren.

Sulaymon Eshkabilov am 27 Jan. 2024

  • Verknüpfen

    Direkter Link zu dieser Antwort

    https://de.mathworks.com/matlabcentral/answers/2075161-use-of-interp2-in-an-arbitrary-dataset#answer_1398481

  • Verknüpfen

    Direkter Link zu dieser Antwort

    https://de.mathworks.com/matlabcentral/answers/2075161-use-of-interp2-in-an-arbitrary-dataset#answer_1398481

In MATLAB Online öffnen

Is this what you wanted to obtain:

% Given DATA:

Data = [ 0.25 0.25 0.5;

0.50 0.60 1.5;

0.75 0.75 3.0];

% Extract x, y, and z from Data

x = Data(:, 1);

y = Data(:, 2);

z = Data(:, 3);

[X,Y]=meshgrid(x,y);

Z = meshgrid(z);

% Interpolate using griddata

[Xq,Yq] = meshgrid(0:.01:1);

Zq = interp2(X,Y,Z,Xq,Yq,'spline');

% Plot the results

figure;

scatter3(x, y, z, 'ro', 'filled'); % Original data points in red

hold on;

surf(Xq, Yq, Zq, 'EdgeColor', 'none', 'FaceAlpha', 0.5); % Interpolated/extrapolated surface

xlabel('X');

ylabel('Y');

zlabel('Z(X,Y)');

title('Interpolation and Extrapolation of Mechanical Property');

Use of interp2 in an arbitrary dataset (10)

2 Kommentare

Keine anzeigenKeine ausblenden

Torsten am 27 Jan. 2024

Direkter Link zu diesem Kommentar

https://de.mathworks.com/matlabcentral/answers/2075161-use-of-interp2-in-an-arbitrary-dataset#comment_3044591

  • Verknüpfen

    Direkter Link zu diesem Kommentar

    https://de.mathworks.com/matlabcentral/answers/2075161-use-of-interp2-in-an-arbitrary-dataset#comment_3044591

Bearbeitet: Torsten am 27 Jan. 2024

@Sulaymon Eshkabilov

You already interpolate (extrapolate) when you assume that (x,y,z) can be extended to (X,Y,Z) as existing database for interpolation with interp2.

Stathis Tingas am 27 Jan. 2024

Direkter Link zu diesem Kommentar

https://de.mathworks.com/matlabcentral/answers/2075161-use-of-interp2-in-an-arbitrary-dataset#comment_3044606

  • Verknüpfen

    Direkter Link zu diesem Kommentar

    https://de.mathworks.com/matlabcentral/answers/2075161-use-of-interp2-in-an-arbitrary-dataset#comment_3044606

Bearbeitet: Stathis Tingas am 27 Jan. 2024

Dear @Sulaymon Eshkabilov, thanks for your response which seems to work fine but you have made a mistake in your Data matrix and this seems to make a difference.

In particular, the 3rd element in the y vector should be 0.35 and not 0.75.

When I try to use 0.35 with your version of the code, I get:

Error using griddedInterpolant

Sample points must be sorted in ascending order.

Error in interp2>makegriddedinterp (line 226)

F = griddedInterpolant(varargin{:});

Error in interp2 (line 134)

F = makegriddedinterp(X, Y, V, method,extrap);

Is there a workaround for this error?

Melden Sie sich an, um zu kommentieren.

Melden Sie sich an, um diese Frage zu beantworten.

Siehe auch

Kategorien

MATLABMathematicsInterpolation

Mehr zu Interpolation finden Sie in Help Center und File Exchange

Tags

  • interp2
  • 2d
  • makegriddedinterp
  • griddedinterpolant

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Es ist ein Fehler aufgetreten

Da Änderungen an der Seite vorgenommen wurden, kann diese Aktion nicht abgeschlossen werden. Laden Sie die Seite neu, um sie im aktualisierten Zustand anzuzeigen.


Translated by Use of interp2 in an arbitrary dataset (13)

Use of interp2 in an arbitrary dataset (14)

Website auswählen

Wählen Sie eine Website aus, um übersetzte Inhalte (sofern verfügbar) sowie lokale Veranstaltungen und Angebote anzuzeigen. Auf der Grundlage Ihres Standorts empfehlen wir Ihnen die folgende Auswahl: .

Sie können auch eine Website aus der folgenden Liste auswählen:

Amerika

  • América Latina (Español)
  • Canada (English)
  • United States (English)

Europa

  • Belgium (English)
  • Denmark (English)
  • Deutschland (Deutsch)
  • España (Español)
  • Finland (English)
  • France (Français)
  • Ireland (English)
  • Italia (Italiano)
  • Luxembourg (English)
  • Netherlands (English)
  • Norway (English)
  • Österreich (Deutsch)
  • Portugal (English)
  • Sweden (English)
  • Switzerland
    • Deutsch
    • English
    • Français
  • United Kingdom(English)

Asien-Pazifik

  • Australia (English)
  • India (English)
  • New Zealand (English)
  • 中国
  • 日本Japanese (日本語)
  • 한국Korean (한국어)

Kontakt zu Ihrer lokalen Niederlassung

Use of interp2 in an arbitrary dataset (2024)

FAQs

How does interp2 work? ›

The interp2 command interpolates between data points. It finds values of a two-dimensional function underlying the data at intermediate points. Interpolation is the same operation as table lookup.

How to interpolate a data set? ›

How to interpolate
  1. Organize your data. First, put the data you've collected into a chart that shows your independent and dependent variables. ...
  2. Consider creating a graph. ...
  3. Select your two points. ...
  4. Enter values into the interpolation equation. ...
  5. Solve for the missing variable.
Oct 16, 2023

What is interpolation in 2 dimensions? ›

Two dimensional interpolation takes a series of (x,y,z) points and generates estimated values for z's at new (x,y) points. Interpolation is used when the function that generated the original (x,y,z) points is unknown. Interpolation is related to, but distinct from, fitting a function to a series of points.

How does image interpolation work? ›

The basic idea of interpolation is quite simple: first, reconstruct a “continuous” image from the discrete input image, then sample this “continuous” image onto the grid of the output image. Interpolation methods differ from the way the “continuous” image is reconstructed.

What are the disadvantages of interpolation? ›

Among its disadvantages is that its solution it is not very precise and data points is not differentiable. Bicubic interpolation in two dimensions, and trilinear interpolation in three dimensions are used when working on gridded or scattered data.

How do you interpolate scattered data? ›

Linear interpolation of scattered data requires a mesh to be constructed using known independent points. This can be done using Delaunay triangulation to obtain simplexes (triangles or their higher dimensional equivalents) for the interpolation function to be applied over.

Which method is best for interpolation? ›

In terms of the ability to fit your data and produce a smooth surface, the Multiquadric method is considered by many to be the best. All of the Radial Basis Function methods are exact interpolators, so they attempt to honor your data.

How does motion interpolation work? ›

Motion interpolation is a process done by high refresh displays where generated frames are inserted between the original frames of a video. Motion interpolation was added to modern LCD televisions to reduce motion blur and make the picture appear smoother and sharper.

How does string interpolation work? ›

In computer programming, string interpolation (or variable interpolation, variable substitution, or variable expansion) is the process of evaluating a string literal containing one or more placeholders, yielding a result in which the placeholders are replaced with their corresponding values.

How does spline interpolation work? ›

That is, instead of fitting a single, high-degree polynomial to all of the values at once, spline interpolation fits low-degree polynomials to small subsets of the values, for example, fitting nine cubic polynomials between each of the pairs of ten points, instead of fitting a single degree-nine polynomial to all of ...

How does bilinear interpolation work? ›

The bilinear interpolation process uses the average of the data at each corner of the rectangle. The weights are based on the separation between the point and the corners for a (x,y) position inside the rectangle. The weight of the corner increases the closer it is to the tip.

Top Articles
What are the pros and cons of leaving a doberman uncropped?
13 Best Elevated Dog Bowls: Raised Eating for Rover!
2016 Hyundai Sonata Refrigerant Capacity
Pr 127 Seat Map
159R Bus Schedule Pdf
Autozone Locations Near Me
Norris Funeral Home Chatham Va Obituaries
Phil Maloof Net Worth
Jeff Siegel Picks Santa Anita
Aita For Helping My Girlfriend Get Over Her Trauma
Sevita Sso Login
J/99 – der neue Hochseerenner
Maine Coon And Bobcat Mix
Pokemon Fire Red Download Pc
Lima Crime Stoppers
The Guardian Crossword Answers - solve the daily Crossword
Lehigh Valley Ironpigs Score
Bardstown Ky Pawn Shops
Meridamoonbeams
Smile 2022 Showtimes Near Savoy 16
Equity Livestock Monroe Market Report
Kentuky Fried Chicken Near Me
Monkey Werx Sitrep 2022
11 Nightlife Spots To Experience In Salem, Oregon
Best Birthday Dinner Los Angeles
Umn Biology
Connection | Scoop.it
Maintenance Required Gear Selector Ecu
Lenscrafters Westchester Mall
Advance Auto.parts Near Me
Stephanie Ruhle's Husband
Calculating R-Value: How To Calculate R-Value? (Formula + Units)
Harness Divine Power 5E Cleric
Lily Spa Roanoke Rapids Reviews
Sunset Time Yesterday
Oklahoma Craigslist Pets
Claudia Capertoni Only Fans
Understanding Turbidity, TDS, and TSS
Tires Shop Santoyo
101 Riddles for Adults That Will Test Your Smarts
Lubbock, Texas hotels, motels: rates, availability
Az610 Flight Status
Myapps Tesla Ultipro Sign In
Quazii Plater Nameplates Profile - Quazii UI
Priscilla 2023 Showtimes Near Regal Escondido
Southern Ute Drum
Puppiwi World : Age, Height, Family, Relationship Status, Net Worth, Wiki, and More Including Exclusive Insights! WikistarFact
50 Shades Of Grey Movie 123Movies
Gotham Chess Twitter
Azpeople Self Service
Dumb Money Showtimes Near Regal Eastview Mall
Southwest Airlines Departures Atlanta
Latest Posts
Article information

Author: Duane Harber

Last Updated:

Views: 6011

Rating: 4 / 5 (71 voted)

Reviews: 86% of readers found this page helpful

Author information

Name: Duane Harber

Birthday: 1999-10-17

Address: Apt. 404 9899 Magnolia Roads, Port Royceville, ID 78186

Phone: +186911129794335

Job: Human Hospitality Planner

Hobby: Listening to music, Orienteering, Knapping, Dance, Mountain biking, Fishing, Pottery

Introduction: My name is Duane Harber, I am a modern, clever, handsome, fair, agreeable, inexpensive, beautiful person who loves writing and wants to share my knowledge and understanding with you.