JMeter Special Series (vii) Aggregation report of 90% Line

JMeter website Original:

90% line-90% of the samples took no more than this time. The remaining samples at least as long as this.

Google Translate: "90% of the sample does not exceed this time, the remaining samples at least as long as this." ”

Click for detailed explanation:

90% line (+ th percentile) is the value below which 90% of the samples fall. The remaining samples too at least as long as the value. This was a standard statistical measure. See, for Example:percentile entry at Wikipedia.

Percentile number of digits:

In statistical terms, if a group of data is sorted from large to small and the corresponding cumulative percentile is calculated, the value of the corresponding data for a 100 percentile is called the percentile of the 100 percentile. Can be expressed as: a group of n observations are arranged by numerical value, for example, the value in the p% position is called the P percentile.

The median is the No. 5000-digit number.

The No. 2500 division is also known as the first four-quartile, denoted by Q1, and the No. 5000 is called the second four-cent (Second quartile), denoted by Q2, and the No. 7500-digit is called the third four-cent (third quartile), expressed in Q3. If the P percentile is a decimal number, it can be full integer.

A scale is a measure of where the data is measured, but what it measures is not necessarily the central location. Percentiles provide information about how individual data items are distributed between the minimum and maximum values. For data with no significant duplication, the p percentile divides it into two parts. The value of the data item with approximately p% is smaller than the p percentile, while the value of the data item with approximately (100-P)% is greater than the percentile of p. The exact definition of P percentile is as follows.

The P percentile is a value that causes at least p% data items to be less than or equal to this value, and at least (100-p)% of the data item is greater than or equal to this value.

The results of entrance examinations in institutions of higher learning are often reported in the form of percentiles. For example, suppose a candidate's original score in the language part of the entrance exam is 54 points. It's not easy to know how his grades are for other students who take the same exam. But if the original score of 54 points corresponds to the No. 7000, we can know that about 70% of the students scored lower than him, and about 30% of students scored higher than him.

In fact, this is the last candidate score example, let me suddenly understand.

If:

There are 10 numbers:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10 by the big to the teenager its arrangement.

The 90th percentile, that is, the 9th number is exactly 9, then his 90%line is 9.

Another set of numbers:

2, 2.1, 2.5, 3, 3.4, 3.4, 4, 4, 4, 4, 5, 5, 5, 5.9, 5.91, 6.8, 8, 12, 24, 24.1 are arranged by the big to the teenager.

Ask for its 90th percentile, the 18th number is 12, and his 90%line is 12.

Explain 90%line again.

A group of numbers is arranged from small to large to find his 90th number (if 12), then 90% of the array will be less than or equal to 12.

The response time used in the performance test will also be significant, i.e. 90% user response time will not exceed 12 seconds.

JMeter Special Series (vii) Aggregation report of 90% Line