R 如何解释“形状”包的矢量角度?
我想弄清楚我用的一些向量角是否计算正确 我有一个模拟的粒子轨迹,数据如下:R 如何解释“形状”包的矢量角度?,r,trigonometry,R,Trigonometry,我想弄清楚我用的一些向量角是否计算正确 我有一个模拟的粒子轨迹,数据如下: track_id track_length frame x y dx dy steplength direction <fctr> <fctr> <dbl> <dbl> <dbl> <dbl>
track_id track_length frame x y dx dy steplength direction
<fctr> <fctr> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
1 Track 1 Track length: 464 0 -0.2779444 0.6532534 0.0000000 0.000000000 0.0000000 0.0000000
2 Track 1 Track length: 464 1 0.9527568 1.6890017 1.2307012 1.035748375 1.6085398 40.0836991
3 Track 1 Track length: 464 2 3.1617740 1.5406508 2.2090172 -0.148350899 2.2139930 -3.8420418
4 Track 1 Track length: 464 3 3.4791213 1.1602548 0.3173472 -0.380396044 0.4953892 -50.1632825
5 Track 1 Track length: 464 4 3.0130556 1.7207842 -0.4660657 0.560529394 0.7289790 129.7426481
6 Track 1 Track length: 464 5 4.1270750 1.7163850 1.1140194 -0.004399235 1.1140281 -0.2262584
7 Track 1 Track length: 464 6 3.5344773 2.2045875 -0.5925977 0.488202537 0.7677980 140.5171189
8 Track 1 Track length: 464 7 1.8244100 2.3753219 -1.7100673 0.170734431 1.7185693 174.2984400
9 Track 1 Track length: 464 8 3.2462738 1.7072696 1.4218637 -0.668052374 1.5709839 -25.1661450
10 Track 1 Track length: 464 9 2.0981822 2.1773816 -1.1480916 0.470112097 1.2406126 157.7322425
if (angle < 0)
angle = angle + 360
方向列的计算方式如下:
方向=180/pi*atan2dy,dx
这给了我一个角度,每个点的向量,以[-180,180]度的形式。我检查了ggplot的箭头功能,角度看起来是正确的。到目前为止还不错
现在,我想使用光栅和图形包的组合来绘制每个xy单元的矢量方向。特别是,我在解释Arrowhead函数的文档时遇到了问题,它说:
角度:箭头相对于x轴的逆时针角度,单位为度[0360];一个值或一个向量
但这需要我的未转换的价值观。这是否意味着他们是正确的?或者它们需要格式化吗?如何从[-180180]到[0360]?只需像这样更改角度域:
track_id track_length frame x y dx dy steplength direction
<fctr> <fctr> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
1 Track 1 Track length: 464 0 -0.2779444 0.6532534 0.0000000 0.000000000 0.0000000 0.0000000
2 Track 1 Track length: 464 1 0.9527568 1.6890017 1.2307012 1.035748375 1.6085398 40.0836991
3 Track 1 Track length: 464 2 3.1617740 1.5406508 2.2090172 -0.148350899 2.2139930 -3.8420418
4 Track 1 Track length: 464 3 3.4791213 1.1602548 0.3173472 -0.380396044 0.4953892 -50.1632825
5 Track 1 Track length: 464 4 3.0130556 1.7207842 -0.4660657 0.560529394 0.7289790 129.7426481
6 Track 1 Track length: 464 5 4.1270750 1.7163850 1.1140194 -0.004399235 1.1140281 -0.2262584
7 Track 1 Track length: 464 6 3.5344773 2.2045875 -0.5925977 0.488202537 0.7677980 140.5171189
8 Track 1 Track length: 464 7 1.8244100 2.3753219 -1.7100673 0.170734431 1.7185693 174.2984400
9 Track 1 Track length: 464 8 3.2462738 1.7072696 1.4218637 -0.668052374 1.5709839 -25.1661450
10 Track 1 Track length: 464 9 2.0981822 2.1773816 -1.1480916 0.470112097 1.2406126 157.7322425
if (angle < 0)
angle = angle + 360