如果索引的索引大于某个值，我试图从数组中删除它们。我希望做这样的事情：
a = ["a", "b", "c"]
b = a.delete_if {|x| x.index > 1 }
我看了drop，delete_if等。我尝试使用each_with_index完成此操作：
new_arr = []
a.each_with_index do |obj, index|
if index > 1
obj.delete
end
new_arry << obj
end
如果数组元素的数组位置大于某个值，我怎么能删除它？
答案 0 :(得分：6)
以下是在index＆gt; = # New Input File Format is as follows
####
# Files
####
InputFile = "CrowdRun_AVCI_1080p_100.yuv" # Input sequence
InputHeaderLength = 0 # If the inputfile has a header, state it's length in byte here
StartFrame = 0 # Start frame for encoding. (0-N)
FramesToBeEncoded = 3 # Number of frames to be coded
FrameRate = 50.0 # Frame Rate per second (0.1-100.0)
SourceWidth = 1920 # Source frame width
SourceHeight = 1080 # Source frame height
SourceResize = 0 # Resize source size for output
OutputWidth = 1920 # Output frame width
OutputHeight = 1080 # Output frame height
ProcessInput = 0 # Filter Input Sequence
Interleaved = 0 # 0: Planar input, 1: Packed input
StandardRange = 0 # 0: Standard range 1: Full range (RGB input)
VideoCode = 1 # Video codes for RGB ==> YUV conversions
TraceFile = "trace_enc.txt" # Trace file
ReconFile = "test_rec.yuv" # Reconstruction YUV file
OutputFile = "test.264" # Bitstream
StatsFile = "stats.dat" # Coding statistics file
####
# Encoder Control
####
ProfileIDC = 122 # Profile IDC (66=baseline, 77=main, 88=extended; FREXT Profiles: 100=High, 110=High 10, 122=High 4:2:2, 244=High 4:4:4, 44=CAVLC 4:4:4 Intra)
IntraProfile = 1 # Activate Intra Profile for FRExt (0: false, 1: true)
# (e.g. ProfileIDC=110, IntraProfile=1 => High 10 Intra Profile)
LevelIDC = 51 # Level IDC (e.g. 20 = level 2.0)
IntraPeriod = 1 # Period of I-pictures (0=only first)
IDRPeriod = 1 # Period of IDR pictures (0=only first)
AdaptiveIntraPeriod = 1 # Adaptive intra period
AdaptiveIDRPeriod = 0 # Adaptive IDR period
IntraDelay = 0 # Intra (IDR) picture delay (i.e. coding structure of PPIPPP... )
EnableIDRGOP = 0 # Support for IDR closed GOPs (0: disabled, 1: enabled)
EnableOpenGOP = 0 # Support for open GOPs (0: disabled, 1: enabled)
QPISlice = 28 # Quant. param for I Slices (0-51)
QPPSlice = 28 # Quant. param for P Slices (0-51)
FrameSkip = 0 # Number of frames to be skipped in input (e.g 2 will code every third frame).
# Note that this now excludes intermediate (i.e. B) coded pictures
ChromaQPOffset = 0 # Chroma QP offset (-51..51)
DisableSubpelME = 0 # Disable Subpixel Motion Estimation (0=off/default, 1=on)
SearchRange = 32 # Max search range
MEDistortionFPel = 0 # Select error metric for Full-Pel ME (0: SAD, 1: SSE, 2: Hadamard SAD)
MEDistortionHPel = 2 # Select error metric for Half-Pel ME (0: SAD, 1: SSE, 2: Hadamard SAD)
MEDistortionQPel = 2 # Select error metric for Quarter-Pel ME (0: SAD, 1: SSE, 2: Hadamard SAD)
MDDistortion = 2 # Select error metric for Mode Decision (0: SAD, 1: SSE, 2: Hadamard SAD)
SkipDeBlockNonRef = 0 # Skip Deblocking (regardless of DFParametersFlag) for non-reference frames (0: off, 1: on)
ChromaMCBuffer = 1 # Calculate Color component interpolated values in advance and store them.
# Provides a trade-off between memory and computational complexity
# (0: disabled/default, 1: enabled)
ChromaMEEnable = 0 # Take into account Color component information during ME
# (0: only first component/default,
# 1: All Color components - Integer refinement only
# 2: All Color components - All refinements)
ChromaMEWeight = 1 # Weighting for chroma components. This parameter should have a relationship with color format.
NumberReferenceFrames = 5 # Number of previous frames used for inter motion search (0-16)
PList0References = 0 # P slice List 0 reference override (0 disable, N <= NumberReferenceFrames)
Log2MaxFNumMinus4 = 0 # Sets log2_max_frame_num_minus4 (-1 : based on FramesToBeEncoded/Auto, >=0 : Log2MaxFNumMinus4)
Log2MaxPOCLsbMinus4 = -1 # Sets log2_max_pic_order_cnt_lsb_minus4 (-1 : Auto, >=0 : Log2MaxPOCLsbMinus4)
GenerateMultiplePPS = 0 # Transmit multiple parameter sets. Currently parameters basically enable all WP modes (0: diabled, 1: enabled)
ResendPPS = 0 # Resend PPS (with pic_parameter_set_id 0) for every coded Frame/Field pair (0: disabled, 1: enabled)
MbLineIntraUpdate = 0 # Error robustness(extra intra macro block updates)(0=off, N: One GOB every N frames are intra coded)
RandomIntraMBRefresh = 0 # Forced intra MBs per picture
#####
# B Slices
#####
NumberBFrames = 0 # Number of B coded frames inserted (0=not used)
QPBSlice = 30 # Quant. param for B slices (0-51)
BRefPicQPOffset = -1 # Quantization offset for reference B coded pictures (-51..51)
DirectModeType = 1 # Direct Mode Type (0:Temporal 1:Spatial)
DirectInferenceFlag = 1 # Direct Inference Flag (0: Disable 1: Enable)
BList0References = 0 # B slice List 0 reference override (0 disable, N <= NumberReferenceFrames)
BList1References = 1 # B slice List 1 reference override (0 disable, N <= NumberReferenceFrames)
# 1 List1 reference is usually recommended for normal GOP Structures.
# A larger value is usually more appropriate if a more flexible
# structure is used (i.e. using HierarchicalCoding)
BReferencePictures = 0 # Referenced B coded pictures (0=off, 1=B references for secondary layer, 2=B references for primary layer)
HierarchicalCoding = 0 # B hierarchical coding (0= off, 1= 2 layers, 2= 2 full hierarchy, 3 = explicit)
HierarchyLevelQPEnable = 1 # Adjust QP based on hierarchy level (in increments of 1). Overrides BRefPicQPOffset behavior.(0=off, 1=on)
ExplicitHierarchyFormat = "b1r0b3r0b2e2b0e2b4r2" # Explicit Enhancement GOP. Format is {FrameDisplay_orderReferenceQP}.
# Valid values for reference type is r:reference, e:non reference.
ReferenceReorder = 1 # Reorder References according to Poc distance for HierarchicalCoding (0=off, 1=enable, 2=use when LowDelay is set)
PocMemoryManagement = 1 # Memory management based on Poc Distances for HierarchicalCoding (0=off, 1=on, 2=use when LowDelay is set)
BiPredMotionEstimation = 1 # Enable Bipredictive based Motion Estimation (0:disabled, 1:enabled)
BiPredMERefinements = 3 # Bipredictive ME extra refinements (0: single, N: N extra refinements (1 default)
BiPredMESearchRange = 16 # Bipredictive ME Search range (8 default). Note that range is halved for every extra refinement.
BiPredMESubPel = 2 # Bipredictive ME Subpixel Consideration (0: disabled, 1: single level, 2: dual level)
#####
# SP Frames
#####
SPPicturePeriodicity = 0 # SP-Picture Periodicity (0=not used)
QPSPSlice = 36 # Quant. param of SP-Slices for Prediction Error (0-51)
QPSISlice = 36 # Quant. param of SI-Slices for Prediction Error (0-51)
QPSP2Slice = 35 # Quant. param of SP/SI-Slices for Predicted Blocks (0-51)
SI_FRAMES = 0 # SI frame encoding flag (0=not used, 1=used)
SP_output = 0 # Controls whether coefficients will be output to encode switching SP frames (0=no, 1=yes)
SP_output_name = "low_quality.dat" # Filename for SP output coefficients
SP2_FRAMES = 0 # switching SP frame encoding flag (0=not used, 1=used)
SP2_input_name1 = "high_quality.dat" # Filename for the first swithed bitstream coefficients
SP2_input_name2 = "low_quality.dat" # Filename for the second switched bitstream coefficients
#####
# Output Control, NALs
#####
SymbolMode = 1 # Symbol mode (Entropy coding method: 0=UVLC, 1=CABAC)
OutFileMode = 0 # Output file mode, 0:Annex B, 1:RTP
PartitionMode = 0 # Partition Mode, 0: no DP, 1: 3 Partitions per Slice
####
# CABAC context initialization
####
ContextInitMethod = 1 # Context init (0: fixed, 1: adaptive)
FixedModelNumber = 0 # model number for fixed decision for inter slices ( 0, 1, or 2 )
######
# Interlace Handling
#####
PicInterlace = 0 # Picture AFF (0: frame coding, 1: field coding, 2:adaptive frame/field coding)
MbInterlace = 0 # Macroblock AFF (0: frame coding, 1: field coding, 2:adaptive frame/field coding, 3: frame MB-only AFF)
IntraBottom = 0 # Force Intra Bottom at GOP Period
#####
# Weighted Prediction
#####
WeightedPrediction = 0 # P picture Weighted Prediction (0=off, 1=explicit mode)
WeightedBiprediction = 0 # B picture Weighted Prediciton (0=off, 1=explicit mode, 2=implicit mode)
ChromaWeightSupport = 1 # Enable consideration of weights for Chroma components
UseWeightedReferenceME = 1 # Use weighted reference for ME (0=off, 1=on)
WPMethod = 1 # WP method (0: DC based, 1: LMS based)
WPIterMC = 0 # Iterative Motion compensated based weighted prediction method
EnhancedBWeightSupport = 0 # Enhanced B Weight support (needs revisit if we wish to merge with WPMethod)
WPMCPrecision = 0 # Improved Motion Compensation Precision using WP based methods.
# Clones WP references with slightly modified rounding offsets (Requires RDPictureDecision and GenerateMultiplePPS) :
# 0: disabled (default)
# 1: Up to one additional coding pass. Ref0 is 0, ref1 is 0 with a -1 offset
# 2: Up to two additional coding passes. (1) Ref0 is 0, ref1 is 0 with a -1 offset, (1) Ref0 is 0 with a -1 offset, ref1 is 0
WPMCPrecFullRef = 0 # Increases the number of references in the reference picture lists to account
# for the lost reference slot when reordering is used during a coding pass in WPMCPrecision for reference replication.
# The number of references in non-reordered passes stays unchanged
WPMCPrecBSlice = 1 # 2: Apply rounding on every B slice. This efectively disables the evaluation of alternative QPs during RDPictureDecision.
# 1: Disable rounding for non-reference B slices. Non-reference B slices are evaluated for alternative QPs during RDPictureDecision.
# 0: Disable rounding for B slices.
#####
# Picture based Multi-pass encoding
#####
RDPictureDecision = 0 # Perform multiple pass coding and make RD optimal decision among them
RDPSliceBTest = 0 # Perform Slice level RD decision between P and B slices.
RDPictureMaxPassISlice = 1 # Max number of coding passes for I slices, valid values [1,3], default is 1
RDPictureMaxPassPSlice = 2 # Max number of coding passes for P slices, valid values [1,6], default is 2
RDPictureMaxPassBSlice = 3 # Max number of coding passes for B slices, valid values [1,6], default is 3
RDPictureFrameQPPSlice = 0 # Perform additional frame level QP check (QP+/-1) for P slices, 0: disabled (default), 1: enabled
RDPictureFrameQPBSlice = 0 # Perform additional frame level QP check (QP+/-1) for B slices, 0: disabled, 1: enabled (default)
RDPictureDeblocking = 0 # Perform another coding pass to check non-deblocked picture, 0: disabled (default), 1: enabled
RDPictureDirectMode = 0 # Perform another coding pass to check the alternative direct mode for B slices, , 0: disabled (default), 1: enabled
#####
# Deblocking filter parameters
#####
DFParametersFlag = 0 # Configure deblocking filter (0=parameters below ignored, 1=parameters sent)
# Note that for pictures with multiple slice types,
# only the type of the first slice will be considered.
DFDisableRefISlice = 0 # Disable deblocking filter in reference I coded pictures (0=Filter, 1=No Filter).
DFAlphaRefISlice = 0 # Reference I coded pictures Alpha offset div. 2, {-6, -5, ... 0, +1, .. +6}
DFBetaRefISlice = 0 # Reference I coded pictures Beta offset div. 2, {-6, -5, ... 0, +1, .. +6}
DFDisableNRefISlice = 0 # Disable deblocking filter in non reference I coded pictures (0=Filter, 1=No Filter).
DFAlphaNRefISlice = 0 # Non Reference I coded pictures Alpha offset div. 2, {-6, -5, ... 0, +1, .. +6}
DFBetaNRefISlice = 0 # Non Reference I coded pictures Beta offset div. 2, {-6, -5, ... 0, +1, .. +6}
DFDisableRefPSlice = 0 # Disable deblocking filter in reference P coded pictures (0=Filter, 1=No Filter).
DFAlphaRefPSlice = 0 # Reference P coded pictures Alpha offset div. 2, {-6, -5, ... 0, +1, .. +6}
DFBetaRefPSlice = 0 # Reference P coded pictures Beta offset div. 2, {-6, -5, ... 0, +1, .. +6}
DFDisableNRefPSlice = 0 # Disable deblocking filter in non reference P coded pictures (0=Filter, 1=No Filter).
DFAlphaNRefPSlice = 0 # Non Reference P coded pictures Alpha offset div. 2, {-6, -5, ... 0, +1, .. +6}
DFBetaNRefPSlice = 0 # Non Reference P coded pictures Beta offset div. 2, {-6, -5, ... 0, +1, .. +6}
DFDisableRefBSlice = 0 # Disable deblocking filter in reference B coded pictures (0=Filter, 1=No Filter).
DFAlphaRefBSlice = 0 # Reference B coded pictures Alpha offset div. 2, {-6, -5, ... 0, +1, .. +6}
DFBetaRefBSlice = 0 # Reference B coded pictures Beta offset div. 2, {-6, -5, ... 0, +1, .. +6}
DFDisableNRefBSlice = 0 # Disable deblocking filter in non reference B coded pictures (0=Filter, 1=No Filter).
DFAlphaNRefBSlice = 0 # Non Reference B coded pictures Alpha offset div. 2, {-6, -5, ... 0, +1, .. +6}
DFBetaNRefBSlice = 0 # Non Reference B coded pictures Beta offset div. 2, {-6, -5, ... 0, +1, .. +6}
#####
# Error Resilience / Slices
#####
SliceMode = 1 # Slice mode (0=off 1=fixed #mb in slice 2=fixed #bytes in slice 3=use callback)
SliceArgument = 50 # Slice argument (Arguments to modes 1 and 2 above)
num_slice_groups_minus1 = 0 # Number of Slice Groups Minus 1, 0 == no FMO, 1 == two slice groups, etc.
slice_group_map_type = 0 # 0: Interleave, 1: Dispersed, 2: Foreground with left-over,
# 3: Box-out, 4: Raster Scan 5: Wipe
# 6: Explicit, slice_group_id read from SliceGroupConfigFileName
slice_group_change_direction_flag = 0 # 0: box-out clockwise, raster scan or wipe right,
# 1: box-out counter clockwise, reverse raster scan or wipe left
slice_group_change_rate_minus1 = 85 #
SliceGroupConfigFileName = "sg0conf.cfg" # Used for slice_group_map_type 0, 2, 6
UseRedundantPicture = 0 # 0: not used, 1: enabled
NumRedundantHierarchy = 1 # 0-4
PrimaryGOPLength = 10 # GOP length for redundant allocation (1-16)
# NumberReferenceFrames must be no less than PrimaryGOPLength when redundant slice enabled
NumRefPrimary = 1 # Actually used number of references for primary slices (1-16)
#####
# Search Range Restriction / RD Optimization
#####
RestrictSearchRange = 2 # restriction for (0: blocks and ref, 1: ref, 2: no restrictions)
RDOptimization = 1 # rd-optimized mode decision
# 0: RD-off (Low complexity mode)
# 1: RD-on (High complexity mode)
# 2: RD-on (Fast high complexity mode - not work in FREX Profiles)
# 3: with losses
# 4: RD-on (High complexity mode) with negative skip bias
I16RDOpt = 0 # perform rd-optimized mode decision for Intra 16x16 MB
# 0: SAD-based mode decision for Intra 16x16 MB
# 1: RD-based mode decision for Intra 16x16 MB
SubMBCodingState = 1 # submacroblock coding state
# 0: lowest complexity, do not store or reset coding state during sub-MB mode decision
# 1: medium complexity, reset to master coding state (for current mode) during sub-MB mode decision
# 2: highest complexity, store and reset coding state during sub-MB mode decision
DistortionSSIM = 0 # Compute SSIM distortion. (0: disabled/default, 1: enabled)
DistortionMS_SSIM = 0 # Compute Multiscale SSIM distortion. (0: disabled/default, 1: enabled)
SSIMOverlapSize = 8 # Overlap size to calculate SSIM distortion (1: pixel by pixel, 8: no overlap)
DistortionYUVtoRGB = 0 # Calculate distortion in RGB domain after conversion from YCbCr (0:off, 1:on)
CtxAdptLagrangeMult = 0 # Context Adaptive Lagrange Multiplier
# 0: disabled (default)
# 1: enabled (works best when RDOptimization=0)
FastCrIntraDecision = 1 # Fast Chroma intra mode decision (0:off, 1:on)
DisableThresholding = 0 # Disable Thresholding of Transform Coefficients (0:off, 1:on)
DisableBSkipRDO = 0 # Disable B Skip Mode consideration from RDO Mode decision (0:off, 1:on)
BiasSkipRDO = 0 # Negative Bias for Skip/DirectSkip modes (0: off, 1: on)
ForceTrueRateRDO = 0 # Force true rate (even zero values) during RDO process
SkipIntraInInterSlices = 0 # Skips Intra mode checking in inter slices if certain mode decisions are satisfied (0: off, 1: on)
WeightY = 1 # Luma weight for RDO
WeightCb = 1 # Cb weight for RDO
WeightCr = 1 # Cr weight for RDO
##########################################################################################
# Explicit Lambda Usage
##########################################################################################
UseExplicitLambdaParams = 0 # Use explicit lambda scaling parameters (0:disabled, 1:enable lambda weight, 2: use explicit lambda value)
UpdateLambdaChromaME = 0 # Update lambda given Chroma ME consideration
FixedLambdaISlice = 0.1 # Fixed Lambda value for I slices
FixedLambdaPSlice = 0.1 # Fixed Lambda value for P slices
FixedLambdaBSlice = 0.1 # Fixed Lambda value for B slices
FixedLambdaRefBSlice = 0.1 # Fixed Lambda value for Referenced B slices
FixedLambdaSPSlice = 0.1 # Fixed Lambda value for SP slices
FixedLambdaSISlice = 0.1 # Fixed Lambda value for SI slices
LambdaWeightISlice = 0.65 # scaling param for I slices. This will be used as a multiplier i.e. lambda=LambdaWeightISlice * 2^((QP-12)/3)
LambdaWeightPSlice = 0.68 # scaling param for P slices. This will be used as a multiplier i.e. lambda=LambdaWeightPSlice * 2^((QP-12)/3)
LambdaWeightBSlice = 0.68 # scaling param for B slices. This will be used as a multiplier i.e. lambda=LambdaWeightBSlice * 2^((QP-12)/3)
LambdaWeightRefBSlice = 0.68 # scaling param for Referenced B slices. This will be used as a multiplier i.e. lambda=LambdaWeightRefBSlice * 2^((QP-12)/3)
LambdaWeightSPSlice = 0.68 # scaling param for SP slices. This will be used as a multiplier i.e. lambda=LambdaWeightSPSlice * 2^((QP-12)/3)
LambdaWeightSISlice = 0.65 # scaling param for SI slices. This will be used as a multiplier i.e. lambda=LambdaWeightSISlice * 2^((QP-12)/3)
LossRateA = 5 # expected packet loss rate of the channel for the first partition, only valid if RDOptimization = 3
LossRateB = 0 # expected packet loss rate of the channel for the second partition, only valid if RDOptimization = 3
LossRateC = 0 # expected packet loss rate of the channel for the third partition, only valid if RDOptimization = 3
FirstFrameCorrect = 0 # If 1, the first frame is encoded under the assumption that it is always correctly received.
NumberOfDecoders = 30 # Numbers of decoders used to simulate the channel, only valid if RDOptimization = 3
RestrictRefFrames = 0 # Doesnt allow reference to areas that have been intra updated in a later frame.
处返回a sans元素的一些其他方法，这可能更好地表达为“返回第一个index元素”。以下全部返回index）。
["a", "b"] 非破坏性（即a = ["a", "b", "c", "d", "e"]
index = 2
不会改变）
a 破坏性（a[0,index]
index.times.map { |i| a[i] }
被修改或“变异”）
a答案 1 :(得分：4)
答案 2 :(得分：3)
Array#first为您提供前n个元素。
b = a.first(1)
# => ["a"]
如果你想以破坏性的方式去做，那么这样做：
a.pop(a.length - 1)
a # => ["a"]
答案 3 :(得分：1)
您可以追加with_index：
a = ["a", "b", "c"]
a.delete_if.with_index { |x, i| i > 1 }
a #=> ["a", "b"]
另一个例子：
a = ("a".."z").to_a
a.delete_if.with_index { |x, i| i.odd? }
#=> ["a", "c", "e", "g", "i", "k", "m", "o", "q", "s", "u", "w", "y"]
答案 4 :(得分：0)
根据你的问题，＆＃34;如果数组元素的数组位置大于某个值，我怎么能删除它？＆＃34; 。
我假设你想要的是你拥有的最终数组应该只包含指定索引之前的元素。
你可以这样做：
your_array.select { |element| your_array.index(element) < max_index }
E.g
figures = [1,2,3,4,5,6]
figures.select{ |fig| figures.index(fig) < 3 }
# => [1, 2, 3]