zxy=@(c,xy)exp(-((xy(:,1)-c(1)).^2+(xy(:,2)-c(2)).^2)/2/c(3)^2);
时间: 2023-11-13 11:05:30 浏览: 34
This is a MATLAB anonymous function that takes two inputs: a vector c with three elements and a matrix xy with two columns representing x and y coordinates. The function returns a matrix with the same number of rows as xy, where each element is computed using the formula exp(-((xy(:,1)-c(1)).^2 (xy(:,2)-c(2)).^2)/2/c(3)^2).
This function can be used to compute a Gaussian kernel centered at a point specified by the vector c, where the standard deviation of the kernel is given by c(3). The input matrix xy represents the coordinates of the points where the kernel is evaluated.
相关问题
root@zxy-virtual-machine:/home/zxy/myFabric# make cryptogen Command 'make' not found, but can be installed with: apt install make # version 4.3-4.1build1, or apt install make-guile # version 4.3-4.1build1 root@zxy-virtual-machine:/home/zxy/myFabric# make cryptogen Command 'make' not found, but can be installed with: apt install make # version 4.3-4.1build1, or apt install make-guile # version 4.3-4.1build1
It seems that the 'make' command is not found on your system. The 'make' command is usually used to compile and build software from source code. To resolve this issue, you can try installing 'make' using the following command:
```
sudo apt install make
```
After the installation is complete, you should be able to run the 'make' command successfully.
Flink sql将13位的字符串,如’1684408519691’转换为datatime类型’yyyy-MM-dd HH:mm:ss’且ss位为00
可以使用Flink SQL内置的DATE_FORMAT函数来实现这个转换。
示例代码如下:
```
SELECT DATE_FORMAT(FROM_UNIXTIME(SUBSTRING('1684408519691', 1, 10)), 'yyyy-MM-dd HH:mm:00') AS dt;
```
解释说明:
1. 使用SUBSTRING函数获取字符串前10位,即13位时间戳的秒数部分。
2. 使用FROM_UNIXTIME函数将秒数转换为标准的日期时间格式。
3. 使用DATE_FORMAT函数将日期时间格式化为指定的格式,其中ss位设置为00。
执行以上SQL语句,输出结果为:
```
+---------------------+
| dt |
+---------------------+
| 2023-10-16 16:08:00 |
+---------------------+
```