从文件加载时倍频程无法识别值

Question

我有一个以制表符分隔的值文件，我加载该文件并将其转换为一个表，其中的值是标量。从表中拾取值时，它不会识别所有值。如果我直接创建与矩阵完全相同的值，它会这样做
(tab1.a == tab2.a)'给出ans = 1 1 0 0 0 0 1，表明值3到6不同。2.2204e-16的差异表明这是一个数字精度的问题，但我怎么能允许呢？我使用Octave版本6.4.0

clear all; clc;
pkg load tablicious

function pick = tabpick(tab, a, b);
pick = ((tab.a==a) & (tab.b==b));
if ~sum(pick)  % no match
error("Selection not dataset !!n");
endif
pick = table2struct( tab(pick,:));
return
endfunction

% create table direct
m = [ 1.315 1.7
1.315   2.19
1.66    2.1
1.66    2.3
1.66    3.03
1.76    3.28
1.9   2.4  ];
a = m(:,1);  
b = m(:,2); 
tab1 = table(a, b);
% prettyprint the table
pp(tab1)
% show type of variables
typeinfo(tab1.a), typeinfo(tab1.a(1))

% load table from tsv file
fid = fopen('table_test.txt', 'r');
tab_file = textscan(fid,"%f %f",'delimiter','t', 'Headerlines',1);
a = tab_file{1};
b = tab_file{2};
tab2   = table(a, b);
pp(tab2)
typeinfo(tab2.a), typeinfo(tab2.a(1))

% compare the two: They are different !
(tab1.a == tab2.a)'

% we can pick any value by menu
pick=menu('pick b', cellstr(num2str(tab2.b)));
table2struct( tab2(pick,:))

% pick from tab1 works fine
tabpick(tab1, 1.315, 2.19)
tabpick(tab1, 1.76, 3.28)

% pick from tab2 fails on second one
tabpick(tab2, 1.315, 2.19)
tabpick(tab2, 1.76, 3.28)

Answer 1

差值给出了线索。使用

function pick = tabpick(tab, a, b);
pick = (abs(tab.a-a)< 1e-15) & (abs(tab.b-b) <1e-15);
...