getting arrays into matrix

Question

Vilmos Popelyak 2022-5-12

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1717550-getting-arrays-into-matrix

回答： Binaya 2023-11-2

hi all, newbie here. working on an RT60 calculator in the app creator, and i'm trying to arrange several arrays into one matrix, but i keep getting an error message for it, and i can't seem to figure out why it doesn't work. here's a screenshot of it. please help

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Vilmos Popelyak 2022-5-12

it's meant to be a reverberation calculator for rooms where you can input the dimensions, and the materials covering the surfaces, and based on the set coefficients, it will determine the reverberation times on 4 different frequencies.

not going to lie, this isn't my forte, but i need it for a uni assignment, so please be patient lol

I'll just copy in the full code to avoid related inconveniences in the future:

%width

RoomWidth = app.RoomwidthEditField.Value;

FloorWidth = app.FloorwidthEditField_2.Value;

CeilingWidth = app.CeilingwidthEditField.Value;

LeftWallWidth = app.LeftwallwidthEditField.Value;

RightWallWidth = app.BackwallwidthEditField.Value;

BackWallWidth = app.BackwallwidthEditField.Value;

FrontWallWidth = app.FrontwallwidthEditField.Value;

%length

RoomLength = app.RoomlengthEditField.Value;

FloorLength = app.FloorlengthEditField.Value;

CeilingLength = app.CeilinglengthEditField.Value;

LeftWallLength = app.LeftwalllengthEditField.Value;

RightWallLength = app.RightwalllengthEditField.Value;

BackWallLength = app.BackwalllengthEditField.Value;

FrontWallLength = app.FrontwalllengthEditField.Value;

%height

RoomHeight = app.RoomheightEditField.Value;

%calculate area of secondary material surface

AreaLWall2 = LeftWallLength * LeftWallWidth;

AreaRWall2 = RightWallLength * RightWallWidth;

AreaFWall2 = FrontWallWidth * FrontWallLength;

AreaBWall2 = BackWallWidth * BackWallLength;

AreaFloor2 = FloorLength * FloorWidth;

AreaCeiling2 = CeilingLength * CeilingWidth;

%Calculate area of room surfaces

AreaLWall = RoomLength * RoomHeight - AreaLWall2;

AreaRWall = RoomLength * RoomHeight - AreaRWall2;

AreaFWall = RoomWidth * RoomHeight - AreaFWall2;

AreaBWall = RoomWidth * RoomHeight - AreaBWall2;

AreaFloor = RoomLength * RoomWidth - AreaFloor2;

AreaCeiling = RoomLength * RoomWidth - AreaCeiling2;

%Convert dropdown options from string (text) to numbers

LeftWallMaterial = str2double(app.LeftwallmaterialDropDown.Value);

RightWallMaterial = str2double(app.RightwallmaterialDropDown.Value);

FrontWallMaterial = str2double(app.FrontwallmaterialDropDown.Value);

BackWallMaterial = str2double(app.BackwallmaterialDropDown.Value);

CeilingMaterial = str2double(app.CeilingmaterialDropDown.Value);

FloorMaterial = str2double(app.FloormaterialDropDown.Value);

SecondaryMaterialWall = str2double(app.SecondarywallmaterialDropDown.Value);

SecondaryMaterialCeiling = str2double(app.SecondaryceilingmaterialDropDown.Value);

SecondaryMaterialFloor = str2double(app.SecondaryfloormaterialDropDown.Value);

%Coefficients (125Hz 250Hz 500Hz 10000Hz 2000Hz 40000Hz)

Unpaintedconcrete = [0.01, 0.01, 0.02, 0.02, 0.02, 0.05];

Plasterboardonbattens = [0.31, 0.33, 0.14, 0.10, 0.10, 0.12]; %Plasterboard on 25mm battens

Parquetteonconcrete = [0.04, 0.04, 0.07, 0.06,0.06, 0.07];

Mediumcarpet = [0.50, 0.10, 0.30, 9.50, 0.65, 0.70]; %Medium pile carpet on sponge rubber underlay 10mm

Rockwoolpanel = [0.46, 0.93, 1, 1, 1, 1];

Drapery = [0.14, 0.35, 0.53, 0.75, 0.7, 0.6];

Glass = [0.30, 0.20, 0.10, 0.07, 0.05, 0.02];

%turn coefficient arrays into matrix

Matrix = [Unpaintedconcrete; Plasterboardonbattens; Parquetteonconcrete; Mediumcarpet; Rockwoolpanel; Drapery; Glass];

%get coefficient based on drop down option

Coefficient1 = Matrix(LeftWallMaterial,:);

Coefficient2 = Matrix(RightWallMaterial,:);

Coefficient3 = Matrix(FrontWallMaterial,:);

Coefficient4 = Matrix(BackWallMaterial,:);

Coefficient5 = Matrix(FloorMaterial,:);

Coefficient6 = Matrix(CeilingMaterial,:);

Coefficient7 = Matrix(SecondaryMaterialWall,:);

Coefficient8 = Matrix(SecondaryMaterialFloor,:);

Coefficient9 = Matrix(SecondaryMaterialCeiling,:);

%calculate absorption of each wall

AbsorptionLW = AreaLWall * Coefficient1;

AbsorptionRW = AreaRWall * Coefficient2;

AbsorptionFW = AreaFWall * Coefficient3;

AbsorptionBW = AreaBWall * Coefficient4;

%absorption of floor and ceiling

AbsorptionFloor = AreaFloor * Coefficient5 ;

AbsorptionCeiling = AreaCeiling * Coefficient6;

%calculate absorption secondary material

AbsorptionLW2 = AreaLWall2 * Coefficient7;

AbsorptionRW2 = AreaRWall2 * Coefficient7;

AbsorptionFW2 = AreaFWall2 * Coefficient7;

AbsorptionBW2 = AreaBWall2 * Coefficient7;

%absorption of floor and ceiling

AbsorptionFloor2 = AreaFloor2 * Coefficient8;

AbsorptionCeiling2 = AreaCeiling2 * Coefficient9;

%Total Absorption or Room

TotalAbsorptionRoom= AbsorptionLW + AbsorptionRW + AbsorptionFW + AbsorptionBW + AbsorptionFloor + AbsorptionCeiling + AbsorptionLW2 + AbsorptionRW2 + AbsorptionFW2 + AbsorptionBW2 + AbsorptionFloor2 + AbsorptionCeiling2;

%Sabine Room

RT60 = (0.162* Volume)./ TotalAbsorptionRoom;

app.HzEditField.Value = RT60(1);

app.HzEditField_2.Value = RT60(2);

app.HzEditField_3.Value = RT60(3);

app.HzEditField_4.Value = RT60(4);

app.HzEditField_5.Value = RT60(5);

app.HzEditField_6.Value = RT60(6);

Vilmos Popelyak 2022-5-12

the 'dbstop if error' came back with this message besides the original error message:

rethrow(exception);

In base workspace.

Jan 2022-5-12

编辑：Jan 2022-5-12

在 MATLAB Online 中打开

@Vilmos Popelyak: Of course it does. This is the purpose of the dbstop command. When Matlab stops at the error, you can examine the locvally used variables and find out, why the index is not a positive integer.

If this code is encapsulated in y TRY/CATCH block, this command stops Matlab more powerful:

dbstop if caught error

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Answer 1

Binaya 2023-11-2

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1717550-getting-arrays-into-matrix#answer_1345196

Hi Vilmos,

Based on your description, it seems that you want to address an error that occurs when executing the code, specifically the error message "Index in position 1 is invalid. Array indices must be positive integers or logical values."

Upon reviewing the provided code, it appears that the error arises from passing the value of the "LeftwallmaterialDropDown" as an index to an array using the function “str2double()”.

To resolve this error, please ensure that the value selected in the "Leftwallmaterial" drop-down menu in the app designer is not a character, negative number, zero, or a fractional number. These types of values are not valid as array indices.

I hope this helps.

Regards 

Binaya