floatdrawCircle(invec2p,invec2offset,infloatr){returnlength(p-offset)-r;} 先看输入的值,p代表任意点的坐标,offset即圆心和原点的偏移量,r就是圆的半径。而length方法会返回输入的向量的模长。 那么有个问题,offset和r我们很好设置,这个p怎么来?空间中任意点,那不就是无数个点了么? 采样空间中的任意点...
{R}} 被作者称为 fall-off function,这里简单解释下它的意义:[^WMW86] 最早提出用一种场函数 {f(x)} 描述软体,具体做法是在场景设置几个点 {\{p_n\}},每个点有其影响范围 {\{r_n\}},则 {f(x)=g({\|x-p_i\|\over r_n})},其中 {r_i,~p_i} 取最近的点,所以相当于渲染 {f(x)}...
function ST_Latitude [1] New function ST_Longitude [1] New function ST_Transform [1] Geography support in ST_Distance...GEOMETRYCOLLECTION [1 2 3] Optional SPATIAL keyword in R-tree index clauses [1] Ability to specify length unit in ST_Distance ...
This paper applies the distance function approach for stochastic frontier analysis (SFA) to compare research and development (R&D) efficiency across 24 nations during 1998–2005. In this multiple input–output framework, R&D expenditure stock and R&D manpower were inputs, while patents, scientific jo...
For faster performance whenYcontains many observations that have many nearest points inX, you can setSortIndicestofalse. In this case,rangesearchreturns the indices of the nearest points in no particular order. WhenSortIndicesistrue, the function arranges the indices of the nearest points in ascendi...
If observation i in X or observation j in Y contains NaN values, the function pdist2 returns NaN for the pairwise distance between i and j. Therefore, D1(1,1), D1(1,2), and D1(1,3) are NaN values. Define a custom distance function nanhamdist that ignores coordinates with NaN ...
All thresholds for distance partitioning, specified as anM-element real-valued vector. The function calculates partitions based on each threshold value provided inallThresholds. Note that multiple thresholds can result in the same partition, and the function outputpartitions, returned as anN-by-Qmatrix...
The relationship of this distance and the exposure mass percentage (probability) based on droplet distribution was then obtained by curve fitting, as seen in Fig. 4. The social distance index Pd is expressed as a function of distance, as shown in Eq. (10), where the R2 = 0.9189.(...
Conformational isomerism is not trivial, and it is known that the conformation change in biological macromolecules can result in dramatic function differences (e.g., toxic vs. nontoxic)20. For inorganic (or inorganic-organic hybrid) nanoparticles (NPs), the concept of conformational isomerism has ...
The total map lengths were derived from the linkage maps and the likelihoods for different numbers of crossovers in the bivalent were inferred from the observed number of crossovers (see ‘Inference of crossover frequency’ below). Implementation of the p0(k) function in R is provided in the ...