从更精细的比例图中提取数据点 [英] Extracting data points from a plot on a finer scale

问题描述

我想从Matlab中的绘图图中提取数据.因此，我做了以下事情:

I want to extract data from a plotted graph I have in matlab. As such, I did the following:

f = openfig('spline.fig');
xdata = get(gco, 'xdata');
ydata = get(gco, 'ydata');

这确实分别为我提供了x和y的数据点，但是在每个点之间都有一个0.5步长(例如 1、1.5、2、2.5 ... ).我希望能获得比该数据更好的数据点(例如例如 1、1.1、1.2、1.3、1.4 ...)，以及与这些x坐标相对应的y坐标.我该怎么办?

This does give me the data points of x and y respectively, but with a step of 0.5 between each points (e.g 1, 1.5, 2, 2.5...). I was hoping to get finer data points than that (e.g 1, 1.1, 1.2, 1.3, 1.4...), and the corresponding y-coordinates to these x-coordinates. How can I do this?

推荐答案

您获取ydata的方式对我不起作用，我会使用:

The way you got your ydata didn't work for me, I would use:

open testfigure.fig 
D = get(gca, 'Children');
ydata = get(D, 'YData'); 

我获得的ydata包含用于绘制图形的原始y数据.

The ydata I obtained contains the original y-data used to plot the figure.

现在，如果您需要更精细的数据分辨率，则必须自己进行插值. 这是有关如何将ydata插值为0.1分辨率的简短示例:

Now, if you need a finer resolution in the data you will have to interpolate that yourself. Here's short example of how to interpolate this ydata to a resolution of 0.1:

1. 定义新的x值xi以查找y的值

1. Define new x values xi to find y values for

xi = 0:0.1:10;

对ydata进行插值以在xi处找到新的yi值:

Interpolate ydata to find new yi values at xi:

yi = interp1(xdata, ydata, xi); %// Using the default "linear"

您应该阅读要使用的方法(例如 样条)，这取决于您的数据和要求.

You should read up on the kind of method you want to use (e.g. nearest neighbour, spline), this depends on your data and requirements.

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