7, programming Abas notes seven rough estimation
If you sow the seed of behavior, you reap the fruit of habit. Sow the seed of habit, you can harvest the fruit of character; If you sow the seed of character, you reap the fruit of destiny.”
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To be honest, toad didn’t know there were rough estimates in the program until he read this article. Because Toad had been studying machinery when he was a student (he also wanted to study computer after the college entrance examination, but was stopped by his family. However, he chose to study machinery, but he went to work in the IT industry by a strange coincidence of circumstances), there were estimates in many scenes in the machinery, but the program also had to be estimated.
What does the program estimate?
For example, how much water flows out of the Yangtze River in a day? So this is going to be an estimate.
What knowledge is needed to estimate?
In fact, the Chinese may be good at some basic skills, such as rounding and unit conversion. Certainly not without some of our daily experience. Finally, we need practice practice practice.
For example, how much storage is needed to estimate a 2 million data structure? This is actually quite common.
However, the author mentions a trick we often use in our work, which is to get key parameters. For example, the network speed, 1000Mbit/s is actually how many megabits per second? You can estimate the approximate time required for a terabyte file transfer.
Two points to note when estimating:
L Safety factor
Estimation is not guaranteed to be 100% correct, so when we estimate, we need to have a margin, to give ourselves six fallbacks. Workstations, you get this all the time. The supervisor asked you if this thing could be done in 2 weeks. What do you say?
‘Maybe two or three weeks,’ Toad usually answered. Ha ha.
L Little’s law
This little law, said Toad, was the first he had heard of it. “The average number of objects in the queue is the product of the progress rate and the average residence time”
If a nightclub holds 60 people and no one stays for 3 hours, the rate of entry is 20 people per hour. So if there are 20 people in line outside, it will take an hour to digest.