replace numbers smaller than certain threshold with zero

I have a large data sheet (see below) in .csv format. I want to replace the numbers in each column and row with zero if it is smaller than a certain value, let’s say 0.1.

Could anyone give me a hand? Thanks a lot.

I guess it can be done with sed as in this example

BCC_ACR_CR  BCC_ACR_CU  BCC_ACR_FE  BCC_ACR_MN  BCC_ACR_MO
0.2826027   3.89E-12    0.58420346  2.23E-13    0.2105587
0.27986588  3.80E-12    0.58501168  2.27E-13    0.20890705
0.27986588  3.80E-12    0.58501168  2.27E-13    0.20890705
0.27986588  3.80E-12    0.58501168  2.27E-13    0.20890705
0.28038733  3.81E-12    0.58196375  5.88E-05    0.21239142
0.26855376  3.27E-12    0.60364524  2.06E-13    0.11205138
0.27220042  3.28E-12    0.60349573  2.08E-13    0.11530944
0.36294869  3.14E-12    0.50515464  1.64E-13    3.12E-12
0.36294869  3.14E-12    0.50515464  1.64E-13    3.12E-12
0.40837234  3.07E-12    0.47202708  1.73E-13    3.03E-12
0.3643896   3.25E-12    0.50431576  1.63E-13    3.14E-12
0.3643896   3.25E-12    0.50431576  1.63E-13    3.14E-12
0.35885258  3.21E-12    0.50978952  1.64E-13    3.12E-12

Answer

Here is one for GNU awk. Field separator is assumed to be a run of space so empty fields are not allowed:

$ gawk -v value=0.1 '                        # give treshold values as parameter
BEGIN { RS="( +n?|n)" }                    # every field is considered a record
{
    ORS=RT                                   # RT stores actualized RS
    if($0<value)                             # comparison
        $0=sprintf("0%-" length()-1 "s","")  # format data to fit the field
}1' file                                     # output

Output:

BCC_ACR_CR  BCC_ACR_CU  BCC_ACR_FE  BCC_ACR_MN  BCC_ACR_MO
0.2826027   0           0.58420346  0           0.2105587
0.27986588  0           0.58501168  0           0.20890705
0.27986588  0           0.58501168  0           0.20890705
0.27986588  0           0.58501168  0           0.20890705
0.28038733  0           0.58196375  0           0.21239142
0.26855376  0           0.60364524  0           0.11205138
0.27220042  0           0.60349573  0           0.11530944
0.36294869  0           0.50515464  0           0       
0.36294869  0           0.50515464  0           0       
0.40837234  0           0.47202708  0           0       
0.3643896   0           0.50431576  0           0       
0.3643896   0           0.50431576  0           0       
0.35885258  0           0.50978952  0           0