std::numeric_limits<float>::infinity()
时间: 2023-09-20 14:03:29 浏览: 54
This is a constant value in the C++ standard library that represents positive infinity for the floating-point data type 'float'. It can be used to compare against other values to determine if they are larger or smaller than infinity. For example:
```
float x = std::numeric_limits<float>::infinity();
float y = 10.0f;
if (y < x) {
// y is smaller than infinity
}
if (x < y) {
// infinity is larger than y
}
```
Note that comparisons involving infinity must be done carefully, as they can lead to unexpected behavior such as NaN (not a number) results.
相关问题
std::numeric_limits infinity
`std::numeric_limits` 是 C++ 中的一个模板类,它提供了许多有关基本数据类型(比如 `int`、`float`、`double` 等)的信息,如最大值、最小值、精度等。其中,`std::numeric_limits<T>::infinity()` 函数可以返回类型 `T` 的正无穷大值。例如,`std::numeric_limits<double>::infinity()` 返回 `double` 类型的正无穷大值。
#include <iostream> #include <pcl/io/pcd_io.h> #include <opencv2/core/core.hpp> #include <opencv2/highgui/highgui.hpp> int main() { pcl::PointCloud<pcl::PointXYZI>::Ptr cloud(new pcl::PointCloud<pcl::PointXYZI>); pcl::io::loadPCDFile("test.pcd", *cloud); float max_intensity = -std::numeric_limits<double>::infinity(); float min_intensity = std::numeric_limits<double>::infinity(); for (const auto& point : *cloud) { max_intensity = std::max(max_intensity, point.intensity); min_intensity = std::min(min_intensity, point.intensity); } double intensity_range = max_intensity - min_intensity; for (auto& point : *cloud) { point.intensity = 255 * (point.intensity - min_intensity) / intensity_range; } cv::Mat rgb_image(cloud->height, cloud->width, CV_8UC3); for (int i = 0; i < cloud->size(); ++i) { rgb_image.at<cv::Vec3b>(i) = cv::Vec3b(cloud->at(i).intensity, 0, 0); } cv::imwrite("output_image.png", rgb_image); return 0; }
这段代码是用于将给定的点云文件(PCD)转换为图像,并在图像中显示每个点的强度值,其中强度值被映射为红色通道的像素值。但是,当运行此代码时,可能会遇到“Failed to find match for field 'intensity'”错误,这是因为点云文件中可能不包含强度值(Intensity)字段,或者该字段的名称不是“intensity”(例如,可能是“inten”或“intensity_value”)。在这种情况下,您需要查看PCD文件的结构,以确定强度值的名称,并相应地更新代码中的点云类型和字段名称。