The phrase "almost sparse" is correct and usable in written English.
It can be used to describe something that is nearly lacking in quantity or density, but not entirely so.
Example: "The landscape was almost sparse, with only a few scattered trees dotting the horizon."
Alternatives: "nearly empty" or "barely populated".
For example, almost sparse signals (compressible signals) are more likely to occur in applications than exactly k-sparse vectors, (e.g., the wavelet transform of an image consists mostly of small coefficients and a few large coefficients).
Wavelet transformations that preserve the local characteristics of a sparse signal can be regarded as "almost" sparse in the "frequency" domain; in general, for sparse signals, the more similar the transformation matrix is to an identity matrix, the sparser the signal is in the transform domain.
On a Friday last August in Providence, Mr. Murphey and Matthew Gross, an executive producer, were lounging in Mr. Gross's almost uncomfortably sparse office at the end of a hallway, talking through Hunt's relationship with her mother, Joan Hunt, played by Joanna Cassidy.
The site is deceptively easy to use and almost too sparse in its simplicity.
The curvelets allow an almost optimal sparse representation of object with -singularities.
If the subspaces V i are known, then it is possible to pick a basis E i = { e j i } j for each V i and construct a dictionary D = ⋃ i = 1 l E i in which every signal of S has sparsity k (or is almost k sparse).
Polling has been almost as sparse in the competitive or potentially competitive contests in Montana, Indiana, Nevada, Hawaii, Connecticut, Arizona and Nebraska.
In practical cases, s has at most k significant elements and the insignificant elements are set to zero which means s is an almost k-sparse vector.
Mendes' dominating visual style was deliberate and composed, with a minimalist design that provided "a sparse, almost surreal feeling a bright, crisp, hard edged, near Magritte-like take on American suburbia"; Mendes constantly directed his set dressers to empty the frame.
Mr. Towner, for his part, kept things sparse, almost austere, making each chord feel solemn and illuminated.
