sppeak: Identification of Peaks of a Mid-infrared Spectra
In spftir: Pre-Processing and Analysis of Mid-Infrared Spectral Region

Description Usage Arguments Value Author(s) Examples

This function allows to identify peaks of a mid-infrared spectra.

1	sppeak(spectra, span = 3, tol = 0.2)

`spectra`	matrix. The matrix of FTIR spectra. The first row corresponds to wavenumber; the remaining rows corresponds to absorbances.
`span`	numeric. Peak detection threshold.
`tol`	numeric. Percentage of the maximum value of the spectrum (positive value).

An object of class sppeak, which is a list of matrices for each of the spectrum.

Claudio Pozo Valenzuela [aut, cre] and Saddys Rodriguez-llamazares [aut]

data(spData)
# Convert data frame to matrix
spectra <- as.matrix(t(spData))
# List of peak detection
pks <- sppeak(spectra=spectra, span=3, tol=0.2)
# Peaks of the first spectrum
pks[[1]]
# Peaks of the second spectrum
pks[[2]]

Loading required package: pracma
             [,1]         [,2]         [,3]         [,4]         [,5]
[1,] 3980.3557700 3968.3028520 3961.5532170 3947.5718320 3942.2685480
[2,]    0.1552488    0.1561192    0.1566825    0.1581786    0.1585918
             [,6]         [,7]        [,8]         [,9]        [,10]
[1,] 3931.6619800 3923.9481120 3916.716361 3902.2528590 3898.8780420
[2,]    0.1596519    0.1602188    0.160714    0.1626401    0.1625264
           [,11]        [,12]        [,13]        [,14]        [,15]
[1,] 3891.646291 3880.5576060 3869.4689210 3862.7192870 3855.9696520
[2,]    0.163368    0.1652046    0.1670741    0.1680825    0.1695909
           [,16]        [,17]        [,18]        [,19]        [,20]
[1,] 3852.112718 3839.0955660 3831.8638150 3817.4003130 3801.9725780
[2,]    0.170078    0.1732783    0.1739309    0.1779457    0.1819154
            [,21]        [,22]        [,23]        [,24]        [,25]
[1,] 3750.3860870 3746.0470360 3733.9941180 3566.6996110 3541.1474240
[2,]    0.2000405    0.2021681    0.2085145    0.3806962    0.3848771
           [,26]        [,27]        [,28]        [,29]        [,30]
[1,] 3535.362023 3527.6481550 3522.3448710 3509.8098360 3501.1317350
[2,]    0.385132    0.3857399    0.3857457    0.3859775    0.3857644
            [,31]        [,32]       [,33]        [,34]        [,35]
[1,] 3496.3105670 3493.8999840 3487.150349 3482.3291820 3466.9014470
[2,]    0.3853945    0.3853934    0.385238    0.3852238    0.3843967
            [,36]       [,37]        [,38]       [,39]        [,40]
[1,] 3463.0445130 3456.294878 3450.5094770 3447.616777 3441.8313760
[2,]    0.3843403    0.383937    0.3835349    0.383545    0.3834322
            [,41]        [,42]        [,43]       [,44]        [,45]
[1,] 3438.4565590 3428.8142240 3419.1718900 3411.940139 3395.5481700
[2,]    0.3833434    0.3833668    0.3838772    0.384351    0.3864641
            [,46]        [,47]        [,48]        [,49]        [,50]
[1,] 3350.2291960 3336.7299280 3332.8729940 3326.1233600 3322.2664260
[2,]    0.3940023    0.3952907    0.3954282    0.3958489    0.3958548
            [,51]        [,52]        [,53]        [,54]        [,55]
[1,] 3319.3737250 3316.4810250 3309.7313910 3299.1248220 3277.9116860
[2,]    0.3958503    0.3957913    0.3957384    0.3950886    0.3927502
            [,56]        [,57]        [,58]        [,59]        [,60]
[1,] 2929.8234030 1867.2381170 1846.0249810 1841.2038140 1828.6687790
[2,]    0.3009468    0.1177905    0.1203984    0.1209864    0.1236664
            [,61]        [,62]        [,63]        [,64]        [,65]
[1,] 1701.8720770 1655.5888700 1653.6604030 1649.8034700 1558.2012900
[2,]    0.1965886    0.2589221    0.2588699    0.2586436    0.2062505
            [,66]        [,67]       [,68]        [,69]        [,70]
[1,] 1458.8852420 1423.2086040 1417.905320 1373.0684630 1340.2845250
[2,]    0.3468832    0.3505877    0.350529    0.3564417    0.3397453
            [,71]        [,72]        [,73]        [,74]        [,75]
[1,] 1302.6794200 1236.6294270 1161.4192160 1083.3163050 1015.3378450
[2,]    0.3148019    0.3434842    0.4897685    0.5018141    0.5594222
            [,76]       [,77]       [,78]       [,79]       [,80]      [,81]
[1,] 1009.0703280 988.3393082 927.5925995 854.3108557 849.4896883 763.672909
[2,]    0.5594424   0.5745512   0.3713076   0.2822128   0.2811563   0.332432
           [,82]       [,83]       [,84]       [,85]       [,86]       [,87]
[1,] 738.1207224 708.2294848 669.1780292 659.0535777 650.3754765 643.6258422
[2,]   0.2965964   0.3479266   0.3424889   0.3437366   0.3453611   0.3475671
           [,88]       [,89]       [,90]       [,91]       [,92]       [,93]
[1,] 639.2867916 608.9134372 606.0207368 597.3426355 575.1652657 554.4342461
[2,]   0.3486652   0.3862006   0.3862756   0.3868022   0.4241819   0.3849494
           [,94]       [,95]       [,96]       [,97]       [,98]       [,99]
[1,] 548.6488452 545.7561448 532.7389930 525.9893587 520.6860746 512.9722068
[2,]   0.3808092   0.3789953   0.4003526   0.4053872   0.4060613   0.3961025
          [,100]      [,101]      [,102]      [,103]      [,104]      [,105]
[1,] 507.1868060 501.8835219 498.0265880 492.2411872 485.9736696 481.6346190
[2,]   0.3906598   0.3915886   0.3866271   0.3831113   0.3792012   0.3783627
          [,106]      [,107]      [,108]      [,109]     [,110]      [,111]
[1,] 474.8849847 466.2068834 458.9751324 454.1539650 447.404331 441.1368132
[2,]   0.3816927   0.3645852   0.3681395   0.3667162   0.366205   0.3699427
          [,112]     [,113]      [,114]      [,115]      [,116]
[1,] 432.4587119 428.601778 419.9236768 411.2455756 404.4959413
[2,]   0.3839221   0.370331   0.3974815   0.3757896   0.3871529
             [,1]         [,2]         [,3]         [,4]         [,5]
[1,] 3432.6711580 3417.7255390 3410.9759050 3407.1189710 3397.9587530
[2,]    0.8540675    0.8687919    0.8731764    0.8765643    0.8812923
             [,6]         [,7]         [,8]         [,9]        [,10]
[1,] 3389.2806520 3378.6740840 3375.7813830 3368.0675160 3359.3894140
[2,]    0.8816325    0.8782572    0.8779269    0.8731145    0.8654675
            [,11]        [,12]       [,13]       [,14]        [,15]       [,16]
[1,] 3349.7470800 2930.3055200 1456.474659 1417.423203 1368.7294130 1339.802409
[2,]    0.8556609    0.3326072    0.265511    0.308115    0.3216626    0.306296
            [,17]        [,18]       [,19]       [,20]       [,21]       [,22]
[1,] 1152.7411150 1079.9414880 1021.123246 928.0747162 708.2294848 671.5886128
[2,]    0.6842798    0.8890612    1.273242   0.2600728   0.2782019   0.2683707
           [,23]       [,24]       [,25]       [,26]       [,27]       [,28]
[1,] 664.3568618 654.7145271 605.5386201 594.9320519 577.0937326 551.5415457
[2,]   0.2757175   0.2788381   0.3523392   0.3510579   0.4043109   0.3240308
           [,29]       [,30]       [,31]       [,32]       [,33]       [,34]
[1,] 546.7203783 529.3641758 521.1681913 498.0265880 491.7590704 488.3842533
[2,]   0.3209303   0.3645762   0.3448455   0.2933342   0.2853665   0.2835228
           [,35]       [,36]       [,37]      [,38]
[1,] 483.0809692 478.7419186 439.2083462 432.940829
[2,]   0.2749126   0.2753651   0.2600005   0.258883