[R] newbie - read.csv creates a (data.frame, table, array, matrix, ...) and plotting one column

Mark Knecht
Sun, 28 Jun 2009 23:02:23 -0000

Hi all,
   Newbie alert. OK, I'm reading the help file using Ted's suggestion
of ?read.csv or ?read.table, etc., and trying to understand exactly
what R has created for me when I do the read.csv command. The overall
header says read.table creates a 'data.frame', which is fine with me
as it works, but throughout the help file I run into the words table,
matrix, array and others. Are these just different names for the same
thing? Or are they subsets of what R considers a 'data.frame'? Or
something else? Maybe just a pointer to a good page in the help file
that explains this would be helpful,if it exists?

   The second question is about plotting one column from data set.
I've used read.csv to read in somethign called PFA_VWAP. row.names,
names and dim all return sensible values. The command
PFA_VWAP_Equity<-PFA_VWAP[,10] seems to load the new variable with the
right data for the equity curve, but how do I plot it?
plot(PFA_VWAP_Equity) gives me a chart that doesn't make sense to me.
Note however that the original values that make up column 10 were
surrounded by quotes so I'm not sure how to tell what sort of data R
thinks is in column 10. Is it numeric or text? I think it's integer
from the last command.

   Console output is shown below. Thanks in advance for being gentle
with a new user. I need to order a good book from Amazon I suppose.
Recommendations?

Cheers,
Mark


> row.names(PFA_VWAP)
  [1] "1"   "2"   "3"   "4"
"5"   "6"   "7"   "8"   "9"
"10"  "11"
 "12"  "13"  "14"  "15"  "16"
"17"  "18"
 [19] "19"  "20"  "21"  "22"
"23"  "24"  "25"  "26"  "27"
"28"  "29"
 "30"  "31"  "32"  "33"  "34"
"35"  "36"
 [37] "37"  "38"  "39"  "40"
"41"  "42"  "43"  "44"  "45"
"46"  "47"
 "48"  "49"  "50"  "51"  "52"
"53"  "54"
 [55] "55"  "56"  "57"  "58"
"59"  "60"  "61"  "62"  "63"
"64"  "65"
 "66"  "67"  "68"  "69"  "70"
"71"  "72"
 [73] "73"  "74"  "75"  "76"
"77"  "78"  "79"  "80"  "81"
"82"  "83"
 "84"  "85"  "86"  "87"  "88"
"89"  "90"
 [91] "91"  "92"  "93"  "94"
"95"  "96"  "97"  "98"  "99"
"100"
"101" "102" "103" "104" "105"
"106" "107" "108"
[109] "109" "110" "111" "112"
"113" "114" "115" "116" "117"
"118"
"119" "120" "121" "122" "123"
"124" "125" "126"
[127] "127" "128" "129" "130"
"131" "132" "133" "134" "135"
"136"
"137" "138" "139" "140" "141"
"142" "143" "144"
[145] "145" "146" "147" "148"
"149" "150" "151" "152" "153"
"154"
"155" "156" "157" "158" "159"
"160" "161" "162"
[163] "163" "164" "165" "166"
"167" "168" "169" "170" "171"
"172"
"173" "174" "175" "176" "177"
"178" "179" "180"
[181] "181" "182" "183" "184"
"185" "186" "187" "188" "189"
"190"
"191" "192" "193" "194" "195"
"196" "197" "198"
[199] "199" "200" "201" "202"
"203" "204" "205" "206" "207"
"208"
"209" "210" "211" "212" "213"
"214" "215" "216"
[217] "217" "218" "219" "220"
"221" "222" "223" "224" "225"
"226"
"227" "228" "229" "230" "231"
"232" "233" "234"
[235] "235" "236" "237" "238"
"239" "240" "241" "242" "243"
"244"
"245" "246" "247" "248" "249"
"250" "251" "252"
[253] "253" "254" "255" "256"
"257" "258" "259" "260" "261"
"262"
"263" "264" "265" "266" "267"
"268" "269" "270"
[271] "271" "272" "273" "274"
"275" "276" "277" "278" "279"
"280"
"281" "282" "283" "284" "285"
"286" "287" "288"
[289] "289" "290" "291" "292"
"293" "294" "295" "296" "297"
"298"
"299" "300" "301" "302" "303"
"304" "305" "306"
[307] "307" "308" "309" "310"
"311" "312" "313" "314" "315"
"316"
"317" "318" "319" "320" "321"
"322" "323" "324"
[325] "325" "326" "327"
> names(PFA_VWAP)
 [1] "TRADE"       "MARK-SYS"    "DATE/TIME"
"PL/SIZE"     "PS
METHOD"   "POS SIZE"    "POS PL"
 [8] "DRAWDOWN"    "DRAWDOWN(%)"
"EQUITY"
> dim(PFA_VWAP)
[1] 327  10
> PFA_VWAP_Equity<-PFA_VWAP[,10]
> PFA_VWAP_Equity
  [1] 9,854.00  10,728.00 10,952.00 10,326.00 10,390.00 10,274.00
10,638.00 10,012.00 10,126.00 10,570.00 10,664.00
 [12] 11,408.00 11,152.00 11,366.00 11,410.00 10,784.00 11,188.00
10,562.00 10,766.00 11,330.00 10,704.00 10,608.00
 [23] 10,812.00 10,186.00 10,300.00 10,044.00 10,028.00 10,072.00
10,006.00 9,870.00  9,794.00  9,748.00  10,002.00
 [34] 8,996.00  9,520.00  9,604.00  10,398.00 10,752.00 10,956.00
11,020.00 11,794.00 11,168.00 11,612.00 11,666.00
 [45] 11,040.00 10,414.00 10,338.00 10,002.00 9,826.00  9,200.00
9,804.00  10,638.00 10,412.00 10,466.00 9,840.00
 [56] 10,404.00 10,508.00 10,872.00 11,156.00 10,030.00 9,404.00
8,778.00  8,722.00  9,016.00  9,340.00  10,034.00
 [67] 9,558.00  9,392.00  9,526.00  9,870.00  9,244.00  9,498.00
9,472.00  9,116.00  9,170.00  8,854.00  8,348.00
 [78] 7,952.00  8,006.00  8,270.00  8,164.00  8,048.00  8,012.00
8,236.00  8,410.00  8,194.00  8,298.00  8,572.00
 [89] 8,636.00  8,350.00  8,354.00  8,348.00  9,122.00  8,846.00
9,940.00  9,994.00  9,368.00  10,292.00 10,186.00
[100] 11,280.00 11,374.00 10,828.00 10,982.00 11,226.00 10,600.00
11,174.00 13,078.00 13,312.00 15,046.00 15,030.00
[111] 15,554.00 16,008.00 15,382.00 14,756.00 14,660.00 15,614.00
14,988.00 15,082.00 15,276.00 15,700.00 15,974.00
[122] 15,548.00 14,922.00 14,296.00 14,640.00 14,764.00 15,238.00
15,232.00 16,416.00 16,650.00 16,024.00 15,398.00
[133] 15,872.00 15,246.00 15,490.00 14,864.00 15,778.00 15,632.00
16,496.00 17,320.00 16,694.00 16,068.00 16,512.00
[144] 16,646.00 17,450.00 18,104.00 18,708.00 19,032.00 19,606.00
19,880.00 19,734.00 19,108.00 20,492.00 21,816.00
[155] 22,280.00 22,554.00 21,928.00 21,302.00 21,396.00 21,670.00
21,944.00 22,378.00 23,692.00 24,036.00 23,750.00
[166] 23,674.00 23,488.00 22,862.00 23,816.00 24,620.00 24,494.00
24,878.00 25,552.00 24,926.00 24,300.00 24,364.00
[177] 24,608.00 23,982.00 24,086.00 23,460.00 23,554.00 22,928.00
23,492.00 22,866.00 22,760.00 23,344.00 24,618.00
[188] 24,982.00 24,976.00 25,280.00 25,744.00 25,118.00 25,112.00
25,336.00 25,830.00 26,364.00 27,958.00 28,232.00
[199] 30,166.00 29,540.00 29,234.00 30,588.00 29,962.00 30,586.00
30,370.00 30,844.00 30,818.00 30,192.00 29,066.00
[210] 30,420.00 30,264.00 31,158.00 31,212.00 31,736.00 31,820.00
32,144.00 31,518.00 31,932.00 31,906.00 31,280.00
[221] 32,034.00 31,748.00 32,672.00 33,136.00 33,490.00 33,494.00
33,768.00 33,142.00 33,346.00 32,720.00 32,744.00
[232] 33,458.00 33,532.00 33,606.00 33,800.00 33,934.00 33,308.00
33,282.00 33,656.00 34,160.00 35,954.00 36,558.00
[243] 36,542.00 35,716.00 36,820.00 37,324.00 37,038.00 37,582.00
40,086.00 40,910.00 41,414.00 41,258.00 41,992.00
[254] 42,146.00 41,520.00 40,834.00 40,208.00 39,582.00 40,416.00
42,720.00 42,094.00 43,328.00 42,702.00 45,546.00
[265] 45,670.00 45,044.00 48,018.00 47,402.00 47,416.00 46,880.00
49,854.00 50,058.00 53,032.00 53,166.00 54,040.00
[276] 53,424.00 53,408.00 52,832.00 52,286.00 52,270.00 51,764.00
51,768.00 51,272.00 50,766.00 50,810.00 50,914.00
[287] 50,358.00 50,352.00 49,826.00 50,330.00 50,404.00 50,468.00
51,052.00 52,006.00 52,460.00 52,464.00 51,558.00
[298] 51,532.00 51,536.00 51,540.00 51,964.00 52,018.00 52,132.00
52,076.00 54,150.00 55,954.00 55,468.00 57,772.00
[309] 57,816.00 57,330.00 57,314.00 58,428.00 57,912.00 57,376.00
58,080.00 58,084.00 58,338.00 57,752.00 57,276.00
[320] 57,310.00 56,304.00 56,498.00 55,892.00 56,446.00 56,920.00
57,004.00 56,648.00
322 Levels: 10,002.00 10,006.00 10,012.00 10,028.00 10,030.00
10,034.00 10,044.00 10,072.00 10,126.00 ... 9,994.00
>
> typeof(PFA_VWAP)
[1] "list"
> typeof(PFA_VWAP[,10])
[1] "integer"
>