decimal in wrong position when dividing a 1x10 column by single variable.

Question

Matthew 2023-8-31

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2015166-decimal-in-wrong-position-when-dividing-a-1x10-column-by-single-variable

编辑： Torsten 2023-8-31

F = [0;1650;3400;5200;6850;7750;8150;8500;8750;9000];
A = (0.4/2)^2 * pi();
sigma = F/A
sigma = 10×1
1.0e+04 *

         0
    1.3130
    2.7056
    4.1380
    5.4511
    6.1673
    6.4856
    6.7641
    6.9630
    7.1620

% my problem occures when i divide F/A. The decimal place is shifted over 4 positions to the left

% the answers are the same, just the decimal place is off.

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Torsten 2023-8-31

编辑：Torsten 2023-8-31

You see the 1.0e+04 above with which the values in the column have to be multiplied ? Or what is your question ?

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Answer 1

Walter Roberson 2023-8-31

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2015166-decimal-in-wrong-position-when-dividing-a-1x10-column-by-single-variable#answer_1297731

在 MATLAB Online 中打开

format long g
F = [0;1650;3400;5200;6850;7750;8150;8500;8750;9000];
A = (0.4/2)^2 * pi();
sigma = F/A
sigma = 10×1
1.0e+00 *

                         0
          13130.2828050814
          27056.3403256222
          41380.2852038928
          54510.5680089742
          61672.5404481094
          64855.6393099473
          67640.8508140555
          69630.2876027042
          71619.7243913529

The answers were not wrong: you were just overlooking the 1.0e+04 * just before the numbers. When you use the (default) format short then if you have numbers above about 100 or below about 0.01 in the mix, then the result will be show in scientific notation with a common factor shown at the top.