for i=1:length(n) d(i)=2*tinv(1-alpha/2,n(i)-1)*sigma(i)/sqrt(n(i)); sum_d=sum_d+1/d(i); end
时间: 2024-05-29 18:10:00 浏览: 20
This is a code snippet in MATLAB for computing the confidence interval width for a set of sample sizes and standard deviations.
The loop iterates over the length of the vector "n", which contains the sample sizes. For each sample size, the code computes the confidence interval width using the formula:
width = 2 * tinv(1-alpha/2, n-1) * sigma / sqrt(n)
where "alpha" is the significance level, "sigma" is the standard deviation, and "tinv" is the inverse of the t-distribution function.
The computed width is stored in the vector "d" at the corresponding index. The loop also accumulates the reciprocal of each width in the variable "sum_d".
The final output of the code is the sum of the reciprocal widths, which is commonly used as a measure of the overall precision of the confidence intervals.