Regrouper plusieurs graphes sur une page

Bonjour à tous,
J'ai une analyse avec plusieurs variables et je souhaiterais visualiser sur 2 pages 24 graphiques (soit 12 par page).
Ici, j'ai réduit mes datas à 1 seule variable "Area".
J'ai 8 conditions (Well) notées C03 à C10.
Je souhaite l'histogramme de l'aire pour chaque condition.

En écrivant ce qui suit, j'obtiens un graphique png pour chaque condition.

Code:

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for (i in levels(plate$Well)) { plaque <- plate[which(plate$Well == i),] png(file = sprintf("03_Graphes/Hist_Area_%s.png",i)) hist(plaque$Area,50,main=i) # savePlot (filename="VisuPlate10X_M1", type= "png") dev.off() }

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Maintenant j'aimerais pouvoir créer un pdf ou un graphe png qui me permette de visualiser plusieurs graphes en même temps.
Pour mon data frame complet, j'ai 24 conditions. Je souhaite donc pouvoir visualiser les 24 histogrammes sur la même page ou, s'ils sont trop petits, sur 2 pages (4x3/page).
J'ai testé plusieurs choses (par(mfrow = c(6,4)), layout(matrix...)) mais à chaque fois j'ai un message d'erreur "figure margins too large" ou " dev.off() null device 1" selon ce que j'ai testé.

Je n'arrive pas à débloquer la situation.
Pouvez-vous m'aider s'il vous plait ?
Je vous remercie par avance.
Très bonne journée
Patricia

Voici mon dataframe : plate

Code:

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plate->structure(list(Well = c("C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C03", "C04", "C04", "C04", "C04", "C04", "C04", "C04", "C04", "C04", "C04", "C04", "C04", "C04", "C04", "C04", "C04", "C04", "C04", "C04", "C04", "C04", "C04", "C04", "C04", "C04", "C04", "C04", "C05", "C05", "C05", "C05", "C05", "C05", "C05", "C05", "C05", "C05", "C05", "C05", "C05", "C05", "C05", "C05", "C05", "C05", "C05", "C05", "C05", "C05", "C05", "C05", "C06", "C06", "C06", "C06", "C06", "C06", "C06", "C06", "C06", "C06", "C06", "C06", "C06", "C06", "C06", "C06", "C06", "C06", "C06", "C06", "C06", "C06", "C06", "C06", "C06", "C06", "C07", "C07", "C07", "C07", "C07", "C07", "C07", "C07", "C07", "C07", "C07", "C07", "C07", "C07", "C07", "C07", "C07", "C07", "C07", "C07", "C07", "C07", "C07", "C07", "C07", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C08", "C09", "C09", "C09", "C09", "C09", "C09", "C09", "C09", "C09", "C09", "C09", "C09", "C09", "C09", "C09", "C09", "C09", "C09", "C09", "C09", "C09", "C09", "C09", "C09", "C10", "C10", "C10"), Well_ROI = c("C03_5", "C03_6", "C03_14", "C03_19", "C03_23", "C03_24", "C03_27", "C03_29", "C03_30", "C03_31", "C03_32", "C03_33", "C03_34", "C03_35", "C03_39", "C03_40", "C03_41", "C03_42", "C03_43", "C03_44", "C03_45", "C03_46", "C03_47", "C03_51", "C03_55", "C03_56", "C03_58", "C03_59", "C03_60", "C03_61", "C03_62", "C03_63", "C03_64", "C03_69", "C03_71", "C03_72", "C03_74", "C03_75", "C03_80", "C04_5", "C04_25", "C04_30", "C04_31", "C04_32", "C04_33", "C04_36", "C04_39", "C04_43", "C04_44", "C04_45", "C04_46", "C04_47", "C04_49", "C04_50", "C04_53", "C04_54", "C04_57", "C04_58", "C04_62", "C04_63", "C04_65", "C04_67", "C04_68", "C04_70", "C04_72", "C04_77", "C05_5", "C05_13", "C05_16", "C05_18", "C05_19", "C05_20", "C05_21", "C05_22", "C05_23", "C05_24", "C05_25", "C05_27", "C05_31", "C05_32", "C05_33", "C05_34", "C05_36", "C05_37", "C05_39", "C05_42", "C05_43", "C05_44", "C05_54", "C05_56", "C06_1", "C06_14", "C06_15", "C06_23", "C06_25", "C06_26", "C06_27", "C06_28", "C06_30", "C06_32", "C06_33", "C06_34", "C06_35", "C06_37", "C06_42", "C06_44", "C06_45", "C06_51", "C06_52", "C06_53", "C06_55", "C06_57", "C06_63", "C06_66", "C06_67", "C06_68", "C07_4", "C07_5", "C07_9", "C07_11", "C07_14", "C07_19", "C07_22", "C07_23", "C07_24", "C07_25", "C07_26", "C07_27", "C07_28", "C07_29", "C07_36", "C07_37", "C07_38", "C07_42", "C07_44", "C07_45", "C07_46", "C07_47", "C07_48", "C07_53", "C07_60", "C08_1", "C08_4", "C08_9", "C08_16", "C08_17", "C08_19", "C08_20", "C08_25", "C08_26", "C08_27", "C08_28", "C08_29", "C08_30", "C08_31", "C08_32", "C08_33", "C08_34", "C08_37", "C08_39", "C08_40", "C08_41", "C08_42", "C08_43", "C08_44", "C08_45", "C08_46", "C08_51", "C08_55", "C08_56", "C08_65", "C08_66", "C08_68", "C08_69", "C08_70", "C08_72", "C08_76", "C08_84", "C09_2", "C09_6", "C09_16", "C09_22", "C09_23", "C09_24", "C09_26", "C09_30", "C09_32", "C09_36", "C09_38", "C09_41", "C09_44", "C09_47", "C09_49", "C09_50", "C09_52", "C09_54", "C09_55", "C09_57", "C09_58", "C09_60", "C09_61", "C09_68", "C10_17", "C10_29", "C10_37"), Area = c(21605.17, 48838.57, 86734.26, 39991.84, 12857.47, 37400.54, 28834.4, 17280.83, 69701.01, 20796.42, 41411.28, 63198, 53030.86, 21440.12, 27315.93, 37681.13, 85017.73, 27398.45, 60755.25, 53014.36, 42319.06, 12081.73, 39579.21, 54499.82, 31640.26, 51528.9, 37037.43, 6915.63, 54780.4, 47056.02, 32135.42, 31376.18, 21324.58, 34611.18, 22777.03, 89507.12, 46313.29, 14375.94, 47782.24, 87675.05, 56430.91, 10398.21, 36591.79, 59847.47, 52568.72, 17396.37, 44431.71, 15003.13, 12279.79, 84142.96, 40767.58, 48904.59, 60854.28, 36657.81, 54895.94, 81832.25, 30963.55, 44976.38, 62339.73, 24807.15, 34611.18, 72622.41, 74388.45, 46379.31, 51215.3, 39843.29, 61745.55, 47452.14, 49597.8, 116261.87, 62669.84, 50158.98, 23767.33, 58923.18, 43457.91, 21291.57, 56282.37, 59137.75, 93501.35, 53080.38, 45422.01, 56282.37, 49911.4, 87972.14, 73579.7, 81914.77, 34924.78, 51594.92, 46098.72, 56942.57, 43408.39, 88648.85, 57256.17, 93583.87, 39166.58, 51842.5, 15927.41, 68875.75, 75675.85, 55226.04, 12395.32, 20482.82, 34297.58, 63528.1, 21572.16, 23123.63, 83713.83, 66994.17, 67076.7, 45405.51, 32944.16, 40239.42, 47732.73, 26573.2, 51809.49, 39348.14, 47336.61, 62207.69, 31607.25, 48706.53, 56711.5, 97248.01, 50026.94, 8483.62, 67802.92, 22810.04, 70608.79, 18898.33, 42863.73, 62702.85, 58576.57, 30303.35, 21423.61, 99839.3, 21654.68, 57272.67, 17231.32, 71665.11, 39463.68, 37185.97, 25467.36, 27249.91, 42319.06, 81139.03, 87245.92, 34066.51, 23503.25, 36113.14, 35023.81, 27712.05, 29659.65, 50423.06, 74289.42, 68033.99, 82096.33, 9738, 29329.55, 32911.15, 49531.78, 43210.33, 24146.95, 20928.46, 55919.25, 20812.92, 44976.38, 68892.26, 9473.92, 67934.96, 41609.34, 92857.65, 38341.33, 9985.58, 49284.21, 35502.45, 57107.62, 46098.72, 24229.48, 25186.77, 57355.2, 39463.68, 90711.99, 26177.08, 63214.5, 61431.95, 10167.14, 40718.06, 48194.87, 57635.78, 30881.03, 56959.07, 7278.75, 36030.62, 49713.34, 10398.21, 17000.25, 32515.03, 20944.96, 12378.82, 27827.59, 16208, 26061.54, 71169.96, 28768.38, 62191.19, 69040.8 )), class = "data.frame", row.names = c(NA, -205L))

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