Akira Agata

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MathWorks

678 total contributions since 2016

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Answered
重複したデータを削除する方法
findgroups と splitapply を使う方法はいかがでしょうか？ A = [600 142 30 75 13; 600 141 30 75 14; 600 142 30 80 14]; group = findgroups(A(:,4))...

10 days ago | 0

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plot3でのエラー解決方法
waterfall 関数を使って、ウォーターフォールプロットとして可視化するというのは如何でしょうか？以下は簡単な例です。 % Sample data t = 0:0.1:20; data = zeros(7,numel(t)); for kk...

11 days ago | 0

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How to binarize a grayscale image with multiple thresholds?
Assuming a grayscale image img is a 2D double array, the following code should work: b = img > t1 | img < t2;

17 days ago | 0

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二次元グラフのグラデーション方法
scatter 関数の第4引数で各ポイントの色をコントロールすることができます。例えばご質問のプログラムですと、以下のようになります。 scatter関数の詳細は以下をご参照ください。 https://jp.mathworks.com/help/mat...

24 days ago | 0

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Plotting target points within an n radius plot
How about the following solution? % Data points (N = 10, for example.) numPoints = 10; detRange = 2*pi*(rand(numPoints,1)); ...

24 days ago | 0

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Hi I need help with for loop
No need to use for-loop. How about the following way? % Read data file T1 = readtable('A1_input.txt'); % Postion of (x,y) a...

2 months ago | 0

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Remove noise from image
How about applying median filter? The following is an example: % Read the image and convert it to grya-scale I = imread('gray...

2 months ago | 0

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任意の空セルに数値を代入する方法を教えてください
例えば、以下のような処理はいかがでしょうか？ % Sample cell array (A(1,2) and A(2,2) are empty) A = {'abc',[];123,''}; % Detect empty cell(s) and ...

2 months ago | 0

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二次元グラフとそれに対応したカラーバーを表示させる方法
imagesc を使ってデータをヒートマップとして可視化するのはいかがでしょうか？ご参考までに、簡単な例を作成してみました。 % Sample Data x = linspace(0,2*pi); y = 0.01 + sin(x).^2; ...

2 months ago | 1

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How to convert a cell to matrix?
How about the following way? % Convert to numeric array maxLen = max(cellfun(@numel,A)); A = cellfun(@(x)[x, NaN(1,maxLen - n...

2 months ago | 1

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join tables by categorical variable
Please try innerjoin or outerjoin functions, like: c1 = innerjoin(a,b,'Keys','Var1'); c2 = outerjoin(a,b,'Keys','Var1','MergeK...

3 months ago | 0

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remove nodes without changing the numbering of nodes
How about setting a nodelabel for each node? The following is an example: s = [1 1 1 2 2 3]; t = [2 3 4 3 4 4]; % Create a...

3 months ago | 0

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How to change color bar limits in imagesc?
You can do that task by setting CLim of the axes, like: figure imagesc(rand(4)); ax = gca; ax.CLim = [0 1]; colorbar

3 months ago | 1

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why does the sound with different sampling frequency sounds the same ?
That's the basic of the 'Sampling theorem'. As long as frequency component of the signal is less than Nyquist frequency ( = samp...

3 months ago | 0

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fit結果の各項目毎のプロット
関数fitが出力するcfitオブジェクトの中には、近似曲線の各係数が保存されていますので、これを使ってそれぞれのgauss曲線を描画することができます。 % Sample data x = linspace(0,3*pi); y = sin(x).^...

3 months ago | 0

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Answered
create a matrix using a vector such that each row is one offset of the previous row
If the output matrix is always N-by-3, the following straight-forward way might be enough: matrix = [v(1:end-2);v(2:end-1);v(3:...

3 months ago | 0

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plotコマンドを使わずに、新規figureに元のグラフをコピーをする。
copyobj を使うのはいかがでしょうか？たとえばご質問頂いた例では、以下のようになります。 figure ax1 = axes('Position',[0.1, 0.55 , 0.8182, 0.4091]); ax2 = axes('Pos...

3 months ago | 0

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Answered
グラフ上の座標の取得
figureのコールバック関数 (WindowButtonDownFcn, WindowButtonUpFcn) を使うというのは、いかがでしょうか？たとえば以下のようにすると、マウスの左ボタンを押した時と解放した時の座標を、それぞれ取得することができ...

3 months ago | 0

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Calculate duration from labeled timestamped data.
Thank you for providing your data. I believe the following is an possible solution. I hope this will be somehow helpful for you...

3 months ago | 0

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How to rescale table columns
normalize function can do that task, like: rescaledTable = normalize(yourTable,'range');

3 months ago | 0

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文字列の置き換えについて
条件の数が、ご質問の例のように3個程度であれば、以下のようにして置き換えることができます。 % (1) Straight-forward solution idx = startsWith(A,"A"); A(idx) = "1"; idx = s...

4 months ago | 0

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How to clear dots in image
How about the following? [X,map] = imread('4.png'); X2 = medfilt2(X); imwrite(X2,map,'output.png');

4 months ago | 0

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How to condionally keep unique rows in a table
How about the following? idx = (T.e == 2) & (T.f == 3); T_desired = unique(T(idx,:),'rows'); Or, if your original table T has...

4 months ago | 0

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Answered
Best to import and plot one large csv file
How about using "tall array" ? I believe the following pages should be helpful for your task: https://jp.mathworks.com/help/ma...

4 months ago | 0

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Fill area between plot and the 0-line?
How about using area function? The following is an example: % Sample data x = linspace(0,4*pi,1000); y = sin(x); % Extrac...

4 months ago | 1

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Answered
Finding whether the element of the array is present in the other array and finding the index value
Just in case, let me post an example. If you don't need to think about tolerance, intersect function also works. % Example (de...

4 months ago | 0

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How to find and color circle in a binary image of circles using sliding window through out the image?
Looking at the original image, target regions are filled with plane color. So I tried to apply the entropyfilt to extract the R...

5 months ago | 1

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選択肢から重複を許して並べる順列のパターンを列挙した行列を作る方法
meshgrid や ndgrid 関数を利用する方法では如何でしょうか？たとえば [0 1] から重複を許して3つ選ぶという例ですと、以下のようになります。 [x1,x2,x3] = meshgrid([0 1],[0 1],[0 1]); A ...

5 months ago | 2

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複数の比較対象に関してどのインデックスが一致しているかを知る方法
ismember 関数を使うと、簡単に見つけることができます。たとえばご質問の例ですと、以下のようになります。 A = 11:20; B = [11 12 14 14]; [~,loc] = ismember(B,A); >> loc loc =...

5 months ago | 2

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Answered
classify関数によって得られた確率をROC曲線の出力をすることは可能でしょうか？
classify 関数によって得られた確率（スコア）からROC曲線を出力をすることは可能です。そのためには、プログラムを若干修正する必要があります。まず、perfcurve 関数への入力は、エラーメッセージにもあるように「スコアは浮動小数点のベクトルと...

5 months ago | 4

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