matlab中怎么理解这个语句 if (length_max(ant(l,k+4))-length_cur(l,ant(l,k+4))) >= dist(ca(xx),ca(i))
时间: 2024-04-10 10:29:36 浏览: 47
在MATLAB中,这个语句是一个条件判断语句if语句),用于判断一个条件是否满足。让我们逐步解释这个语句的不同部分:
- `length_max(ant(l,k+4))`:这是一个数组 `length_max` 中的元素,索引为 `ant(l,k+4)`。这部分表示从数组 `length_max` 中取出特定索引处的值。
- `length_cur(l,ant(l,k+4))`:这是一个二维数组 `length_cur` 中的元素,索引为 `(l,ant(l,k+4))`。这部分表示从二维数组 `length_cur` 中取出特定索引处的值。
- `dist(ca(xx),ca(i))`:这是一个函数 `dist` 的调用,传入了两个参数 `ca(xx)` 和 `ca(i)`。这部分表示调用函数 `dist` 并传入特定参数。
- `>=`:这是一个比较运算符,表示大于等于的比较。
整个条件判断语句的意思是,如果 `length_max(ant(l,k+4))-length_cur(l,ant(l,k+4))` 的值大于等于 `dist(ca(xx),ca(i))` 的值,那么条件判断为真。根据条件判断的结果,你可以在 if 语句的代码块中执行特定的操作。
相关问题
用c语言重新实现下列代码功能 while(dyn->d_tag!=DT_NULL){ if(dyn->d_tag == DT_NEEDED){ ++lib->depcnt; } ++dyn; } if(lib->depcnt > 0) lib->dep=malloc(sizeof(LinkMap*)*(lib->depcnt+10)); int cur=0; dyn = lib->dyn; while(dyn->d_tag!=DT_NULL){ if(dyn->d_tag==DT_NEEDED){ lib->dep[cur++] = MapLibrary(str+dyn->d_un.d_val); } ++dyn; }
以下是用 C 语言重新实现上述代码的功能:
```
Elf64_Dyn *dyn = lib->dyn;
int depcnt = 0;
while (dyn->d_tag != DT_NULL) {
if (dyn->d_tag == DT_NEEDED) {
++depcnt;
}
++dyn;
}
if (depcnt > 0) {
lib->dep = (LinkMap **)malloc(sizeof(LinkMap *) * (depcnt + 10));
}
int cur = 0;
dyn = lib->dyn;
while (dyn->d_tag != DT_NULL) {
if (dyn->d_tag == DT_NEEDED) {
lib->dep[cur++] = MapLibrary(str + dyn->d_un.d_val);
}
++dyn;
}
```
其中,`Elf64_Dyn` 是 ELF 文件中的动态链接器数组结构体类型,`LinkMap` 是动态链接器结构体类型,`MapLibrary` 是一个函数,用于加载动态链接库。在这段代码中,我们首先遍历动态链接器数组,统计该共享库所需要的依赖库数量,然后根据数量分配一定大小的依赖库存储空间。接着,我们再次遍历动态链接器数组,将需要的依赖库加载到共享库中。
写出以下程序各步骤的注释: cells_visited_ = 0; // priority buffers threshold_ = lethal_cost_; currentBuffer_ = buffer1_; currentEnd_ = 0; nextBuffer_ = buffer2_; nextEnd_ = 0; overBuffer_ = buffer3_; overEnd_ = 0; memset(pending_, 0, ns_ * sizeof(bool)); std::fill(potential, potential + ns_, POT_HIGH); // set goal int k = toIndex(start_x, start_y); if(precise_) { double dx = start_x - (int)start_x, dy = start_y - (int)start_y; dx = floorf(dx * 100 + 0.5) / 100; dy = floorf(dy * 100 + 0.5) / 100; potential[k] = neutral_cost_ * 2 * dx * dy; potential[k+1] = neutral_cost_ * 2 * (1-dx)*dy; potential[k+nx_] = neutral_cost_*2*dx*(1-dy); potential[k+nx_+1] = neutral_cost_*2*(1-dx)*(1-dy);//*/ push_cur(k+2); push_cur(k-1); push_cur(k+nx_-1); push_cur(k+nx_+2); push_cur(k-nx_); push_cur(k-nx_+1); push_cur(k+nx_*2); push_cur(k+nx_*2+1); }else{ potential[k] = 0; push_cur(k+1); push_cur(k-1); push_cur(k-nx_); push_cur(k+nx_); }
// Initialize cells_visited_ to 0
cells_visited_ = 0;
// Initialize priority buffers
threshold_ = lethal_cost_;
currentBuffer_ = buffer1_;
currentEnd_ = 0;
nextBuffer_ = buffer2_;
nextEnd_ = 0;
overBuffer_ = buffer3_;
overEnd_ = 0;
// Initialize pending_ to false for each cell
memset(pending_, 0, ns_ * sizeof(bool));
// Initialize potential to POT_HIGH for each cell
std::fill(potential, potential + ns_, POT_HIGH);
// Set goal cell
int k = toIndex(start_x, start_y);
if(precise_)
{
// If precise mode is on, calculate potential value for each corner of the goal cell
double dx = start_x - (int)start_x, dy = start_y - (int)start_y;
dx = floorf(dx * 100 + 0.5) / 100;
dy = floorf(dy * 100 + 0.5) / 100;
potential[k] = neutral_cost_ * 2 * dx * dy;
potential[k+1] = neutral_cost_ * 2 * (1-dx)*dy;
potential[k+nx_] = neutral_cost_*2*dx*(1-dy);
potential[k+nx_+1] = neutral_cost_*2*(1-dx)*(1-dy);
// Push the 8 surrounding cells to the current buffer
push_cur(k+2);
push_cur(k-1);
push_cur(k+nx_-1);
push_cur(k+nx_+2);
push_cur(k-nx_);
push_cur(k-nx_+1);
push_cur(k+nx_*2);
push_cur(k+nx_*2+1);
}
else
{
// If precise mode is off, set potential of goal cell to 0 and push the 4 surrounding cells to the current buffer
potential[k] = 0;
push_cur(k+1);
push_cur(k-1);
push_cur(k-nx_);
push_cur(k+nx_);
}