This article deals with a proposal for visualizing the speed of the different sections of the lines of a railway network that has been implemented in the computer algebra system Maple. The idea is to organize the data (the speed in the different sections of the railway network) as a weighted graph. The endpoints of the sections considered are the vertices of the graph and the edges are the sections of the railway lines of the network. The weights of the edges reflect the different speeds in the sections of the network. The vertices of the graph are drawn in the xy plane according to their geographical coordinates. The edges are represented by segments in the xy plane. Vertical rectangles are lifted from these segments according to the weights of the edges (as a kind of wrinkled histogram). Two different methods are proposed to compute the height of the rectangles: one directly considers the difference of speeds with respect to the maximum average speed and the other calculates the height so that the area of the rectangle represents the time required to traverse the section. This way the speeds of the different sections of the lines can be easily visualized (in 3D). The underlying mathematics is elementary, but the implementation is complex and makes extensive use of the possibilities of Maple’s plot package.

中文翻译：

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铁路网络速度可视化的3D建议

本文提出了一个方案，用于可视化已在计算机代数系统Maple中实现的铁路网络的线路各部分的速度。想法是将数据（铁路网络不同部分的速度）组织为加权图。所考虑的部分的端点是图形的顶点，而边是网络的铁路线的部分。边缘的权重反映了网络各部分中的不同速度。图的顶点根据其地理坐标在xy平面中绘制。边缘由xy中的线段表示飞机。根据边缘的权重（作为一种皱纹直方图）从这些线段中提起垂直矩形。提出了两种不同的方法来计算矩形的高度：一种直接考虑速度相对于最大平均速度的差异，另一种计算高度，以使矩形的面积代表横穿截面所需的时间。这样，可以轻松地可视化线的不同部分的速度（在3D中）。基础数学是基本的，但是实现复杂，并且广泛使用了Maple绘图程序包的可能性。